C–H Functionalization: The Ono/Kato/Dairi Synthesis of Fusiocca-1,10(14)-diene-3,8β,16-triol

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Cytochrome P450 ◽  
Iron Catalyst ◽  
State University ◽  
Colorado State University ◽  
Carbon Carbon Bond ◽  
National University ◽  
Rh Catalyst ◽  
Hydride Abstraction ◽  
Osaka Prefecture ◽  
The University

Theodore A. Betley of Harvard University devised (J. Am. Chem. Soc. 2011, 133, 4917) an iron catalyst for inserting the nitrene from 2 into the C–H of 1 to give 3. Bernhard Breit of the Freiburg Institute for Advanced Studies uncovered (J. Am. Chem. Soc. 2011, 133, 2386) a Rh catalyst that effected the intriguing hydration of a terminal alkyne 4 to the allylic ester 5. Yian Shi of Colorado State University specifically oxidized (Org. Lett. 2011, 13, 1548) one of the two allylic sites of 6 to give 7. Kálmán J. Szabó of Stockholm University optimized (J. Org. Chem. 2011, 76, 1503) the allylic oxidation of 9 to 10, using the inexpensive sodium perborate. Masayuki Inoue of the University of Tokyo specifically carbamoylated (Tetrahedron Lett. 2011, 52, 2885) the acetonide 12 to give 14. Stephen Caddick of University College London added (Tetrahedron Lett. 2011, 52, 1067) the formyl radical from 15 to 16 to give 17. Ilhyong Ryu of Osaka Prefecture University and Maurizio Fagnoni of the University of Pavia employed (Angew. Chem. Int. Ed. 2011, 50, 1869) a related strategy to effect the net transformation of 18 to 20. There are many examples of the oxidation of ethers and amines to reactive intermediates that can go on to carbon–carbon bond formation. Ram A. Vishwakarma of the Indian Institute of Integrative Medicine observed (Chem. Commun. 2011, 47, 5852) that with an iron catalyst, the aryl Grignard 22 smoothly coupled with THF 21 to give 23. Gong Chen of Pennsylvania State University effected (Angew. Chem. Int. Ed. 2011, 50, 5192) specific remote C–H arylation of 24, leading to 26. Takahiko Akiyama of Gakushuin University established (J. Am. Chem. Soc. 2011, 133, 2424) conditions for intramolecular hydride abstraction, effecting the conversion of 27 to 28. C–H functionalization in nature is often mediated by cytochrome P450 oxidation. Zhi Li of the National University of Singapore showed (Chem. Commun. 2011, 47, 3284) that a particular cytochrome P450 selectively oxidized 29 to the alcohol 30, leaving the chemically more reactive benzylic position intact.

Metal-Mediated Ring Construction: The Hoveyda Synthesis of (–)-Nakadomarin A

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Preliminary Investigation ◽  
State University ◽  
Colorado State University ◽  
Nakadomarin A ◽  
Sterically Demanding ◽  
National University ◽  
Rh Catalyst ◽  
Seoul National University ◽  
The University ◽  
Technological University

John F. Hartwig of the University of California, Berkeley effected (J. Am. Chem. Soc. 2013, 135, 3375) selective borylation of the cyclopropane 1 to give 2. It would be particularly useful if this borylation could be made enantioselective. Eric M. Ferreira of Colorado State University showed (Org. Lett. 2013, 15, 1772) that the enantomeric excess of 3 was transferred to the highly substituted cyclopropane 4. Antonio M. Echavarren of ICIQ Tarragona demonstrated (Org. Lett. 2013, 15, 1576) that Au-mediated cyclobutene construction could be used to form the medium ring of 6. Joseph M. Fox of the University of Delaware developed (J. Am. Chem. Soc. 2013, 135, 9283) what promises to be a general enantioselective route to cyclobutanes such as 8 by way of the intermediate bicyclobutane (not illustrated). Huw M.L. Davies of Emory University reported (Org. Lett. 2013, 15, 310) a preliminary investigation in this same direction. Masahisa Nakada of Waseda University prepared (Org. Lett. 2013, 15, 1004) the cyclopentane 10 by enantioselective cyclization of 9 followed by reductive opening. Young-Ger Suh of Seoul National University cyclized (Org. Lett. 2013, 15, 531) the lactone 11 to the cyclopentane 12. Xavier Ariza and Jaume Farràs of the Universitat de Barcelona optimized (J. Org. Chem. 2013, 78, 5482) the Ti-mediated reductive cyclization of 13 to 14. The hydrogenation catalyst reduced the intermediate Ti–C bond without affecting the alkene. Erick M. Carreira of ETH Zürich observed (Angew. Chem. Int. Ed. 2013, 52, 5382) that a sterically demanding Rh catalyst mediated the highly diastereoselective cyclization of 15 to 16. The ketone 16 was the key intermediate in a synthesis of the epoxyisoprostanes. Jianrong (Steve) Zhou of Nanyang Technological University used (Angew. Chem. Int. Ed. 2013, 52, 4906) a Pd catalyst to effect the coupling of 17 with the prochiral 18. Geum-Sook Hwang and Do Hyun Ryu of Sungkyunkwan University devised (J. Am. Chem. Soc. 2013, 135, 7126) a boron catalyst to effect the addition of the diazo ester 21 to 20. They showed that the sidechain stereocenter was effective in directing the subsequent hydrogenation of 22.

C–O Ring Formation

2017 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Science And Technology ◽  
State University ◽  
University Of Michigan ◽  
Colorado State University ◽  
Boston University ◽  
Chapel Hill ◽  
Chiral Phosphoric Acid ◽  
National University ◽  
University Of Bristol ◽  
The University

The enantioselective bromocyclization of dicarbonyl 1 to form dihydrofuran 3 using thiocarbamate catalyst 2 was developed (Angew. Chem. Int. Ed. 2013, 52, 8597) by Ying-Yeung Yeung at the National University of Singapore. Access to dihydrofuran 5 from the cyclic boronic acid 4 and salicylaldehyde via a morpholine-mediated Petasis borono-Mannich reaction was reported (Org. Lett. 2013, 15, 5944) by Xian-Jin Yang at East China University of Science and Technology and Jun Yang at the Shanghai Institute of Organic Chemistry. Chiral phosphoric acid 7 was shown (Angew. Chem. Int. Ed. 2013, 52, 13593) by Jianwei Sun at the Hong Kong University of Science and Technology to catalyze the enantioselective acetalization of diol 6 to form tetrahydrofuran 8 with high stereoselectivity. Jan Deska at the University of Cologne reported (Org. Lett. 2013, 15, 5998) the conversion of glutarate ether 9 to enantiopure tetrahy­drofuranone 10 by way of an enzymatic desymmetrization/oxonium ylide rearrange­ment sequence. Perali Ramu Sridhar at the University of Hyderabad demonstrated (Org. Lett. 2013, 15, 4474) the ring-contraction of spirocyclopropane tetrahydropyran 11 to produce tetrahydrofuran 12. Michael A. Kerr at the University of Western Ontario reported (Org. Lett. 2013, 15, 4838) that cyclopropane hemimalonate 13 underwent conver­sion to vinylbutanolide 14 in the presence of LiCl and Me₃N•HCl under microwave irradiation. Eric M. Ferreira at Colorado State University developed (J. Am. Chem. Soc. 2013, 135, 17266) the platinum-catalyzed bisheterocyclization of alkyne diol 15 to fur­nish the bisheterocycle 16. Chiral sulfur ylides such as 17, which can be synthesized easily and cheaply, were shown (J. Am. Chem. Soc. 2013, 135, 11951) by Eoghan M. McGarrigle at the University of Bristol and University College Dublin and Varinder K. Aggarwal at the University of Bristol to stereoselectively epoxidize a variety of alde­hydes, as exemplified by 18. The amine 20-catalyzed tandem heteroconjugate addition/Michael reaction of quinol 19 and cinnamaldehyde to produce bicycle 21 with very high ee was reported (Chem. Sci. 2013, 4, 2828) by Jeffrey S. Johnson at the University of North Carolina, Chapel Hill. Quinol ether 22 underwent facile photorearrangement–cycloaddition to 23 under irradiation, as reported (J. Am. Chem. Soc. 2013, 135, 17978) by John A. Porco, Jr. at Boston University and Corey R. J. Stephenson, now at the University of Michigan.

Heteroaromatic Synthesis: The Tokuyama Synthesis of (−)-Rhazinilam

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Ni Catalyst ◽  
State University ◽  
Colorado State University ◽  
Ru Catalyst ◽  
Opioid Ligands ◽  
University Of Wisconsin ◽  
Rh Catalyst ◽  
Indian Institute Of Science ◽  
The University ◽  
École Polytechnique

Mei-Huey Lin of the National Changhua University of Education rearranged (J. Org. Chem. 2014, 79, 2751) the initial allene derived from 1 to the γ-chloroenone. Displacement with acetate followed by hydrolysis led to the furan 2. A. Stephen K. Hashmi of Ruprecht-Karls-Universität Heidelberg showed (Angew. Chem. Int. Ed. 2014, 53, 3715) that the Au-catalyzed conversion of the bis alkyne 3, mediated by 4, proceeded selectively to give 5. Tehshik P. Yoon of the University of Wisconsin used (Angew. Chem. Int. Ed. 2014, 53, 793) visible light with a Ru catalyst to rearrange the azide 6 to the pyrrole 7. Cheol-Min Park, now at UNIST, found (Chem. Sci. 2014, 5, 2347) that a Ni catalyst reorganized the methoxime 8 to the pyrrole 9. A Rh catalyst converted 8 to the corresponding pyridine (not illustrated). In the course of a synthesis of opioid ligands, Kenner C. Rice of the National Institute on Drug Abuse optimized (J. Org. Chem. 2014, 79, 5007) the preparation of the pyridine 11 from the alcohol 10. Vincent Tognetti and Cyrille Sabot of the University of Rouen heated (J. Org. Chem. 2014, 79, 1303) 12 and 13 under micro­wave irradiation to give the 3-hydroxy pyridine 14. Tomislav Rovis of Colorado State University prepared (J. Am. Chem. Soc. 2014, 136, 2735) the pyridine 17 by the Rh-catalyzed combination of 15 with 16. Fabien Gagosz of the Ecole Polytechnique rearranged (Angew. Chem. Int. Ed. 2014, 53, 4959) the azirine 18, readily available from the oxime of the β-keto ester, to the pyridine 19. Matthias Beller of the Universität Rostock used (Chem. Eur. J. 2014, 20, 1818) a Zn catalyst to mediate the opening of the epoxide 21 with the aniline 20. A Rh cata­lyst effected the oxidation and cyclization of the product amino alcohol to the indole 22. Sreenivas Katukojvala of the Indian Institute of Science Education & Research showed (Angew. Chem. Int. Ed. 2014, 53, 4076) that the diazo ketone 23 could be used to anneal a benzene ring onto the pyrrole 24, leading to the 2,7-disubstituted indole 25.

Organocatalytic Carbocyclic Construction: The You Synthesis of (–)-Mesembrine

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Elevated Pressure ◽  
University Of California ◽  
Cope Rearrangement ◽  
Unsaturated Aldehyde ◽  
State University ◽  
Colorado State University ◽  
13C Isotope ◽  
National University ◽  
Enantioselective Acylation ◽  
The University

Frank Glorius of the Universität Münster devised (Angew. Chem. Int. Ed. 2011, 50, 12626) a catalyst for the enantioselective acylation of a cyclopropene 1 to the ketone 3. Geum-Sook Hwang of Chungnam National University and Do Hyun Ryu of Sungkyunkwan University effected (J. Am. Chem. Soc. 2011, 133, 20708) the enantioselective addition of the diazo ester 5 to an α,β-unsaturated aldehyde 4 to give the cyclopropane 6. We showed (J. Org. Chem. 2011, 76, 7614) that face-selective allylation of an α-iodo enone 7 followed by Suzuki coupling and oxy-Cope rearrangement delivered the cyclopentanone 9. Karl Anker Jørgensen of Aarhus University combined (Org. Lett. 2011, 13, 4790) two organocatalysts to effect the addition of 11 to an α,β-unsaturated aldehyde 10, leading to the cyclopentenone 12. Tomislav Rovis of Colorado State University also used (Chem. Sci. 2011, 2, 1835) two organocatalysts to condense 13 with 14 to give the cyclopentanone 15. Gregory C. Fu, now at CalTech, found (J. Am. Chem. Soc. 2011, 133, 12293) that both enantiomers of the racemic allene 16 combined with 17 to give the cyclopentene 18 in high ee. Piotr Kwiatkowski of the University of Warsaw found (Org. Lett. 2011, 13, 3624) that under elevated pressure (8–10 kbar), enantioselective conjugate addition of nitromethane proceeded well even with a β-substituted cyclohexenone 19. Marco Bella of the Università di Roma observed (Adv. Synth. Catal. 2011, 353, 2648) remarkable diastereoselectivity in the addition of the aldehyde 22 to an activated acceptor 21. Following the procedure of List, Jiong Yang of Texas A&M University cyclized (Org. Lett. 2011, 13, 5696) 24 to 25 in high ee. Bor-Cherng Hong of the National Chung Cheng University described (Synthesis 2011, 1887) the double Michael combination of 26 with 27 to give 28 in high ee. Observing a secondary 13C isotope effect only at the β-carbon of 30, Li Deng of Brandeis University concluded (Chem. Sci. 2011, 2, 1940) that the addition to 29 was stepwise, not concerted. In contrast, the cyclization of 32 to 33 reported (Org. Lett. 2011, 13, 3932) by Tadeusz F. Molinski of the University of California San Diego likely was concerted.

Heteroaromatic Construction: The Sperry Synthesis of (+)-Terreusinone

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Pt Catalyst ◽  
State University ◽  
Keto Ester ◽  
North Carolina State University ◽  
Colorado State University ◽  
Rh Catalyst ◽  
La Jolla ◽  
The University ◽  
Technological University ◽  
Convergent Assembly

Akio Saito and Yuji Hanzawa of Showa Pharmaceutical University found (Tetrahedron Lett. 2011, 52, 4658) that an alkynyl keto ester 1 could be oxidatively cyclized to the furan 2. Eric M. Ferreira of Colorado State University showed (Org. Lett. 2011, 13, 5924) that depending on the conditions, a Pt catalyst could cyclize 3 to either 4 or 5. Shunsuke Chiba of Nanyang Technological University used (J. Am. Chem. Soc. 2011, 133, 13942) Cu catalysis for the oxidation of 6 to the pyrrole 7. Vladimir Gevorgyan of the University of Illinois at Chicago devised (Org. Lett. 2011, 13, 3746) a convergent assembly of the pyrrole 10 from the alkyne 8 and the alkyne 9. Dale L. Boger of Scripps La Jolla extended (J. Am. Chem. Soc. 2011, 133, 12285) the scope of the Diels-Alder addition of the triazine 11 to an alkyne 12 to give the pyridine 13. Tomislav Rovis, also of Colorado State University, used (Chem. Commun. 2011, 47, 11846) a Rh catalyst to add an alkyne 15 to the oxime 14 to give the pyridine 16. Sensuke Ogoshi of Osaka University, under Ni catalysis, added (J. Am. Chem. Soc. 2011, 133, 18018) a nitrile 18 to the diene 17 to give the pyridine 19. Alexander Deiters of North Carolina State University showed (Org. Lett. 2011, 13, 4352) that the complex tethered diyne 20 combined with 21 with high regiocontrol to give 22. Yong-Min Liang of Lanzhou University prepared (J. Org. Chem. 2011, 76, 8329) the indole 24 by cyclizing the alkyne 23. Xiuxiang Qi and Kang Zhao of Tianjin University found (J. Org. Chem. 2011, 76, 8690) that the enamine 25 could be oxidatively cyclized to the indole 26. Kazuhiro Yoshida and Akira Yanagisawa of Chiba University established (Org. Lett. 2011, 13, 4762) that ring-closing metathesis converted the keto ester 27 to the indole 28. Alessandro Palmieri and Roberto Ballini of the Università di Camerino observed (Adv. Synth. Catal. 2011, 353, 1425) that the pyrrole 30 spontaneously added to the nitro acrylate 29 to give an adduct that cyclized to 31 on exposure to acid.

scholarly journals Preface: Modern Heterocycle Synthesis and Functionalization

Synlett ◽  
2021 ◽  
Vol 32 (02) ◽  
pp. 140-141
Author(s):  
Louis-Charles Campeau ◽  
Tomislav Rovis
Keyword(s):  
Active Pharmaceutical Ingredient ◽  
Associate Professor ◽  
Columbia University ◽  
State University ◽  
Heterocycle Synthesis ◽  
Colorado State University ◽  
University Of Toronto ◽  
Process Chemistry ◽  
The University ◽  
Small Molecule Therapeutics

obtained his PhD degree in 2008 with the late Professor Keith Fagnou at the University of Ottawa in Canada as an NSERC Doctoral Fellow. He then joined Merck Research Laboratories at Merck-Frosst in Montreal in 2007, making key contributions to the discovery of Doravirine (MK-1439) for which he received a Merck Special Achievement Award. In 2010, he moved from Quebec to New Jersey, where he has served in roles of increasing responsibility with Merck ever since. L.-C. is currently Executive Director and the Head of Process Chemistry and Discovery Process Chemistry organizations, leading a team of smart creative scientists developing innovative chemistry solutions in support of all discovery, pre-clinical and clinical active pharmaceutical ingredient deliveries for the entire Merck portfolio for small-molecule therapeutics. Over his tenure at Merck, L.-C. and his team have made important contributions to >40 clinical candidates and 4 commercial products to date. Tom Rovis was born in Zagreb in former Yugoslavia but was largely raised in southern Ontario, Canada. He earned his PhD degree at the University of Toronto (Canada) in 1998 under the direction of Professor Mark Lautens. From 1998–2000, he was an NSERC Postdoctoral Fellow at Harvard University (USA) with Professor David A. Evans. In 2000, he began his independent career at Colorado State University and was promoted in 2005 to Associate Professor and in 2008 to Professor. His group’s accomplishments have been recognized by a number of awards including an Arthur C. Cope Scholar, an NSF CAREER Award, a Fellow of the American Association for the Advancement of Science and a ­Katritzky Young Investigator in Heterocyclic Chemistry. In 2016, he moved to Columbia University where he is currently the Samuel Latham Mitchill Professor of Chemistry.

Transition Metal-Mediated Construction of Carbocycles: Dimethyl Gloiosiphone A (Takahashi), Pasteurestin A (Mulzer), and Pentalenene (Fox)

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Transition Metal ◽  
South Florida ◽  
Health Science ◽  
Pt Catalyst ◽  
Max Planck ◽  
Au Catalyst ◽  
Ru Catalyst ◽  
National University ◽  
Rh Catalyst ◽  
The University

There continue to be new developments in transition metal- and lanthanide-mediated construction of carbocycles. Although a great deal has been published on the asymmetric cyclopropanation of styrene, relatively little had been reported for other classes of alkenes. Tae-Jeong Kim of Kyungpook National University has devised (Tetrahedron Lett. 2007, 48, 8014) a Ru catalyst for the cyclopropanation of simple α-olefins such as 1. X. Peter Zhang of the University of South Florida has developed (J. Am.Chem. Soc. 2007, 129, 12074) a Co catalyst for the cyclopropanation of alkenes such as 5 having electron-withdrawing groups. Alexandre Alexakis of the Université de Genève has reported(Angew. Chem. Int. Ed. 2007, 46, 7462) simple monophosphine ligands that enabled enantioselective conjugate addition to prochiral enones, even difficult substrates such as 8. Seunghoon Shin of Hanyang University has found (Organic Lett. 2007, 9, 3539) an Au catalyst that effected the diastereoselective cyclization of 10 to the cyclohexene 11, and Radomir N. Saicic of the University of Belgrade has carried out (Organic Lett. 2007, 9, 5063), via transient enamine formation, the diastereoselective cyclization of 12 to the cyclohexane 13. Alois Fürstner of the Max-Planck- Institut, Mülheim has devised (J. Am. Chem. Soc. 2007, 129, 14836) a Rh catalyst that cyclized the aldehyde 14 to the cycloheptenone 15. Some of the most exciting investigations reported in recent months have been directed toward the direct diastereo- and enantioselective preparation of polycarbocyclic products. Rai-Shung Liu of National Tsing-Hua University has extended (J. Org. Chem. 2007, 72, 567) the intramolecular Pauson-Khand cyclization to the epoxy enyne 16, leading to the 5-5 product 17. Michel R. Gagné of the University of North Carolina has devised (J. Am. Chem. Soc. 2007, 129, 11880) a Pt catalyst that smoothly cyclized the polyene 18 to the 6-6 product 19. Yoshihiro Sato of Hokkaido University and Miwako Mori of the Health Science University of Hokkaido have described (J. Am. Chem. Soc. 2007, 129, 7730) a Ru catalyst for the cyclization of 20 to the 5-6-5 product 21. Each of these processes proceeded with high diastereocontrol.

Stereocontrolled C-O Ring Construction: The Fuwa/Sasaki Synthesis of Attenol A

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Gold Catalysis ◽  
Membered Ring ◽  
Allylic Alcohol ◽  
State University ◽  
Prins Cyclization ◽  
University Of Florida ◽  
University Of Pittsburgh ◽  
Colorado State University ◽  
Institute Of Technology ◽  
The University

Since five-membered ring ethers often do not show good selectivity on equilibration, single diastereomers are best formed under kinetic control. Aaron Aponick of the University of Florida demonstrated (Organic Lett. 2008, 10, 669) that under gold catalysis, the allylic alcohol 1 cyclized to 2 with remarkable diastereocontrol. Six-membered rings also formed with high cis stereocontrol. Ian Cumpstey of Stockholm University showed (Chem. Commun. 2008, 1246) that with protic acid, allylic acetates such as 3 cyclized with clean inversion at the allylic center, and concomitant debenzylation. J. Stephen Clark of the University of Glasgow found (J. Org. Chem. 2008, 73, 1040) that Rh catalyzed cyclization of 5 proceeded with high selectivity for insertion into Ha, leading to the alcohol 6. Saumen Hajra of the Indian Institute of Technology, Kharagpur took advantage (J. Org. Chem. 2008, 73, 3935) of the reactivity of the aldehyde of 7, effecting selective addition of 7 to 8, to deliver, after reduction, the lactone 9. Tomislav Rovis of Colorado State University observed (J. Org. Chem. 2008, 73, 612) that 10 could be cyclized selectively to either 11 or 12. Nadège Lubin-Germain, Jacques Uziel and Jacques Augé of the University of Cergy- Pontoise devised (Organic Lett. 2008, 10, 725) conditions for the indium-mediated coupling of glycosyl fluorides such as 13 with iodoalkynes such as 14 to give the axial C-glycoside 15. Katsukiyo Miura and Akira Hosomi of the University of Tsukuba employed (Chemistry Lett. 2008, 37, 270) Pt catalysis to effect in situ equilibration of the alkene 16 to the more stable regioisomer. Subsequent condensation with the aldehyde 17 led via Prins cyclization to the ether 18. Paul E. Floreancig of the University of Pittsburgh showed (Angew. Chem. Int. Ed. 2008, 47, 4184) that Prins cyclization could be also be initiated by oxidation of the benzyl ether 19 to the corresponding carbocation. Chan-Mo Yu of Sungkyunkwan University developed (Organic Lett. 2008, 10, 265) a stereocontrolled route to seven-membered ring ethers, by Pd-mediated stannylation of allenes such as 21, followed by condensation with an aldehyde.

Functionalization of C-H Bonds: The Baran Synthesis of Dihydroxyeudesmane

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Columbia University ◽  
National Chemical Laboratory ◽  
Chemical Laboratory ◽  
Du Bois ◽  
Rh Catalyst ◽  
Hydride Abstraction ◽  
Mcgill University ◽  
Radical Removal ◽  
The University ◽  
Useful Yield

Arumugam Sudalai of the National Chemical Laboratory, Pune reported (Tetrahedron Lett. 2008, 49, 6401) a procedure for hydrocarbon iodination. With straight chain hydrocarbons, only secondary iodination was observed. Chao-Jun Li of McGill University uncovered (Adv. Synth. Cat. 2009, 351, 353) a procedure for direct hydrocarbon amination, converting cyclohexane 1 into the amine 3. Justin Du Bois of Stanford University established (Angew. Chem. Int. Ed. 2009, 48, 4513) a procedure for alkane hydroxylation, converting 4 selectively into the alcohol 6. The oxirane 8 usually also preferentially ozidizes methines, hydroxylating steroids at the C-14 position. Ruggero Curci of the University of Bari found (Tetrahedron Lett. 2008, 49, 5614) that the substrate 7 showed some C-14 hydroxylation, but also a useful yield of the ketone 9. The authors suggested that the C-7 acetoxy group may be deactivating the C-14 C-H. C-H bonds can also be converted directly to carbon-carbon bonds. Mark E. Wood of the University of Exeter found (Tetrahedron Lett. 2009, 50, 3400) that free-radical removal of iodine from 10 followed by intramolecular H-atom abstraction in the presence of the trapping agent 11 delivered 12 with good diastereo control. Professor Li observed (Angew. Chem. Int. Ed. 2008, 47, 6278) that under Ru catalysis, hydrocarbons such as 13 could be directly arylated. He also established (Tetrahedron Lett. 2008, 49, 5601) conditions for the direct aminoalkylation of hydrocarbons such as 13, to give 17. Huw M. L. Davies of Emory University converted (Synlett 2009, 151) the ester 4 to the homologated diester 19 in preparatively useful yield using the diazo ester 18, the precursor to a selective, push-pull stabilized carbene. Intramolecular bond formation to an unactivated C-H can be even more selective. Guoshen Liu of the Shanghai Institute of Organic Chemistry developed (Organic Lett. 2009, 11, 2707) an oxidative Pd system that cyclized 20 to the seven-membered ring lactam 21 . Professor Du Bois devised (J. Am. Chem. Soc. 2008 , 130, 9220) a Rh catalyst that effected allylic amination of 22, to give 23 with substantial enantiocontrol. Dalibor Sames of Columbia University designed (J. Am. Chem. Soc. 2009, 131, 402) a remarkable cascade approach to C-H functionalization. Exposure of 24 to Lewis acid led to intramolecular hydride abstraction. Cyclization of the resulting stabilized carbocation delivered the tetrahydropyan 25 with remarkable diastereocontrol.

Other Methods for Carbocyclic Construction: The Porco Synthesis of (-)-Hyperibone K

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Oxidative Cyclization ◽  
Florida State University ◽  
State University ◽  
Colorado State University ◽  
Intramolecular Alkylation ◽  
University Of Wisconsin ◽  
Tokyo Institute ◽  
Institute Of Technology ◽  
University Of Bristol ◽  
The University

Varinder K. Aggarwal of the University of Bristol described (Angew. Chem. Int. Ed. 2010, 49, 6673) the conversion of the Sharpless-derived epoxide 1 into the cyclopropane 2. Christopher D. Bray of Queen Mary University of London established (Chem. Commun. 2010, 46, 5867) that the related conversion of 3 to 5 proceeded with high diastereocontrol. Javier Read de Alaniz of the University of California, Santa Barbara, extended (Angew. Chem. Int. Ed. 2010, 49, 9484) the Piancatelli rearrangement of a furyl carbinol 6 to allow inclusion of an amine 7, to give 8. Issa Yavari of Tarbiat Modares University described (Synlett 2010, 2293) the dimerization of 9 with an amine to give 10. Jeremy E. Wulff of the University of Victoria condensed (J. Org. Chem. 2010, 75, 6312) the dienone 11 with the commercial butadiene sulfone 12 to give the highly substituted cyclopentane 13. Robert M. Williams of Colorado State University showed (Tetrahedron Lett. 2010, 51, 6557) that the condensation of 14 with formaldehyde delivered the cyclopentanone 15 with high diastereocontrol. D. Srinivasa Reddy of Advinus Therapeutics devised (Tetrahedron Lett. 2010, 51, 5291) conditions for the tandem conjugate addition/intramolecular alkylation conversion of 16 to 17. Marie E. Krafft of Florida State University reported (Synlett 2010, 2583) a related intramolecular alkylation protocol. Takao Ikariya of the Tokyo Institute of Technology effected (J. Am. Chem. Soc. 2010, 132, 11414) the enantioselective Ru-mediated hydrogenation of bicyclic imides such as 18. This transformation worked equally well for three-, four-, five-, six-, and seven-membered rings. Stefan France of the Georgia Institute of Technology developed (Org. Lett. 2010, 12, 5684) a catalytic protocol for the homo-Nazarov rearrangement of the doubly activated cyclopropane 20 to the cyclohexanone 21. Richard P. Hsung of the University of Wisconsin effected (Org. Lett. 2010, 12, 5768) the highly diastereoselective rearrangement of the triene 22 to the cyclohexadiene 23. Strategies for polycyclic construction are also important. Sylvain Canesi of the Université de Québec devised (Org. Lett. 2010, 12, 4368) the oxidative cyclization of 24 to 25.

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