Flow Chemistry

2015 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Continuous Flow ◽  
Flow Chemistry ◽  
Ethyl Vinyl Ether ◽  
University Of Michigan ◽  
Ethyl Vinyl ◽  
Photochemical Rearrangement ◽  
Osaka Prefecture ◽  
La Jolla ◽  
University Of Bristol ◽  
The University

Timothy F. Jamison at MIT developed (Org. Lett. 2013, 15, 710) a metal-free continuous-flow hydrogenation of alkene 1 using the protected hydroxylamine reagent 2 in the presence of free hydroxylamine. The reduction of nitroindole 4 to the corresponding aniline 5 using in situ-generated iron oxide nanocrystals in continuous flow was reported (Angew. Chem. Int. Ed. 2012, 51, 10190) by C. Oliver Kappe at the University of Graz. A flow method for the MPV reduction of ketone 6 to alcohol 7 was disclosed (Org. Lett. 2013, 15, 2278) by Steven V. Ley at the University of Cambridge. Corey R.J. Stephenson, now at the University of Michigan, developed (Chem. Commun. 2013, 49, 4352) a flow deoxygenation of alcohol 8 to yield 9 using visible light photoredox catalysis. Stephen L. Buchwald at MIT demonstrated (J. Am. Chem. Soc. 2012, 134, 12466) that arylated acetaldehyde 11 could be generated from aminopyridine 10 by diazonium formation and subsequent Meerwein arylation of ethyl vinyl ether in flow. The team of Takahide Fukuyama and Ilhyong Ryu at Osaka Prefecture University showed (Org. Lett. 2013, 15, 2794) that p-iodoanisole (12) could be converted to amide 13 via low-pressure carbonylation using carbon monoxide generated from mixing formic and sulfuric acids. The continuous-flow Sonogashira coupling of alkyne 14 to produce 15 using a Pd-Cu dual reactor was developed (Org. Lett. 2013, 15, 65) by Chi-Lik Ken Lee at Singapore Polytechnic. A tandem Sonogashira/cycloisomerization procedure to convert bromopyridine 16 to aminoindolizine 18 in flow was realized (Adv. Synth. Cat. 2012, 354, 2373) by Keith James at Scripps, La Jolla. A procedure for the Pauson-Khand reaction of alkene 19 to produce the bicycle 20 in a photochemical microreactor was reported (Org. Lett. 2013, 15, 2398) by Jun-ichi Yoshida at Kyoto University. Kevin I. Booker-Milburn at the University of Bristol discovered (Angew. Chem. Int. Ed. 2013, 52, 1499) that irradiation of N-butenylpyrrole 21 in flow produced the rearranged tricycle 22. Professor Jamison described (Angew. Chem. Int. Ed. 2013, 52, 4251) a unique peptide coupling involving the photochemical rearrangement of nitrone 23 to the hindered dipeptide 24 in continuous flow.

Flow Chemistry

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Flow Reactor ◽  
Continuous Production ◽  
Indole Alkaloid ◽  
Flow Chemistry ◽  
Flow Conditions ◽  
University Of Cambridge ◽  
Divided Cell ◽  
Osaka Prefecture ◽  
University Of Bristol ◽  
The University

Arturo Macchi of the University of Ottawa and Dominique M. Roberge of Lonza sum­marized (Org. Process Res. Dev. 2014, 18, 1286) a “toolbox approach” for the evolution from batch to continuous chemical synthesis. Michael D. Organ of York University developed (Org. Process Res. Dev. 2014, 18, 1315) a flow reactor with inline analyt­ics, and Timothy D. White of Eli Lilly described (Org. Process Res. Dev. 2014, 18, 1482) the continuous production of solid products under flow conditions. Electrochemical reduction and oxidation are particularly easy under flow conditions. Steven V. Ley of the University of Cambridge oxidized (Org. Lett. 2014, 16, 4618) 1 under flow conditions, then condensed the product with tryptamine 2 to pre­pare the indole alkaloid Nazlinine 3. Thomas Wirth of Cardiff University electrolyzed (Org. Process Res. Dev. 2014, 18, 1377) the carbonate 4 in a non-divided cell to return the deprotected phenol 5. Timothy Noël of the Eindhoven University of Technology gathered (Chem. Eur. J. 2014, 20, 10562) an overview of photochemical transformations under flow condi­tions. Kevin I. Booker-Milburn of the University of Bristol observed (Chem. Eur. J. 2014, 20, 15226) superior yields for the coupling of 6 with 7 to form 8 under flow compared to batch conditions. Koichi Fukase of Osaka University and Ilhyong Ryu of Osaka Prefecture University converted (Chem. Eur. J. 2014, 20, 12750) 9 selectively to 10 under flow conditions. Alexei A. Lapkin, also of the University of Cambridge, optimized (Org. Process Res. Dev. 2014, 18, 1443) the singlet oxygen conversion of 11 to 12. Shawn K. Collins of the Université de Montréal cyclized (Org. Process Res. Dev. 2014, 18, 1571) 13 to 14. There have been several advances in the use of enzymes under flow conditions. Rodrigo O. M. A. de Souza of the Federal University of Rio de Janeiro found (Org. Process Res. Dev. 2014, 18, 1372) that lipase in a microemulsion-based organogel efficiently converted coupled 15 with 16 to make 17. Timothy F. Jamison of MIT developed (Org. Lett. 2014, 16, 6092) a catch-and-release protocol for the reductive amination of 18 with 19 to give 20.

Preparation of Benzene Derivatives: The Barrett Syntheses of Dehydroaltenuene B and 15G256β

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Aryl Halides ◽  
University Of Michigan ◽  
One Pot ◽  
Aromatic Carboxylates ◽  
Direct Functionalization ◽  
Aryl Tosylates ◽  
La Jolla ◽  
University Of Bristol ◽  
University Of Oslo ◽  
The University

Several new methods for the direct functionalization of Ar-H have appeared. Hisao Yoshida of Nagoya University observed (Chem. Comm. 2008, 4634) that under irradiation, TiO2 in water effected meta hydroxylation of benzonitrile 1 to give the phenol 2. Anisole showed ortho selectivity, while halo and alkyl aromatics gave mixtures. Melanie S. Sanford of the University of Michigan reported (J. Am. Chem. Soc. 2008, 130, 13285) a complementary study of Pd-catalyzed ortho acetoxylation. Jin-Quan Yu of Scripps/La Jolla developed (Angew. Chem. Int. Ed. 2008, 47, 5215) a Pd-catalyzed protocol for ortho halogenation of aromatic carboxylates such as 3. A related protocol (J. Am. Chem. Soc. 2008, 130, 17676) led to ortho arylation. Trond Vidar Hansen of the University of Oslo devised (Tetrahedron Lett. 2008, 49, 4443) a one-pot procedure for the net ortho cyanation of phenols such as 5 to the salicylnitrile 6. Robin B. Bedford of the University of Bristol, Andrew J. M. Caffyn of the University of the West Indies and Sanjiv Prashar of the Universidad Rey Juan Carlos established (Chem. Comm. 2008, 990) a Rh-catalyzed protocol for ortho arylation of phenols such as 7. Laurent Désaubry of the Université Louis Pasteur observed (Tetrahedron Lett. 2008, 49, 4588) regioselective coupling of unsymmetrical difluorobenzenes such as 9 to give the ether 10. Fuk Yee Kwong of Hong Kong Polytechnic University extended (Angew. Chem. Int. Ed. 2008, 47, 6402) Pd-mediated amination to the notoriously difficult mesylates, such as 11. John F. Hartwig of the University of Illinois reported (J. Am. Chem. Soc. 2008, 130, 13848) a related method for the amination of aryl tosylates. Hong Liu of the Shanghai Institute of Materia Medica found (Organic Lett. 2008, 10, 4513) that the Fe-catalyzed amination of aryl halides such as 13 sometimes gave mixtures of regioisomers. Hideki Yorimitsu and Koichiro Oshima of Kyoto University effected (Angew. Chem. Int. Ed. 2008, 47, 5833) Ag-catalyzed Grignard cross coupling with aryl halides, converting 15 into 16. Note that silyl aromatics such as 16 are readily reduced under dissolving metal conditions to give allyl silanes.

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.

Recent Views on Tragedy Ancient and Modern

Traditio ◽  
1959 ◽  
Vol 15 ◽  
pp. 443-448
Author(s):  
Virginia Woods Callahan
Keyword(s):  
Focal Point ◽  
Greek Tragedy ◽  
University Of Michigan ◽  
Classical Philology ◽  
The Arts ◽  
History Of ◽  
Tragic Drama ◽  
Contemporary Painting ◽  
University Of Bristol ◽  
The University

In 1958 the American Council of Learned Societies devoted its thirty-ninth annual meeting to a consideration of ‘the present-day vitality of the classical tradition.’ The focal point in the two-day program was the persistent influence of certain aspects of Greek tragedy upon the arts in our time: two versions of the Antigone (Sophocles’ and Jean Anouilh's) were presented on the same evening; there were lectures on ‘the tragic sense’ in Picasso's Guernica and in contemporary painting and music; but the most striking affirmation of the theme was a lecture on ‘The Vitality of Sophocles’ by Professor H. D. F. Kitto of the University of Bristol. One of the most distinguished of modern classical scholars, Mr. Kitto is well known among American students for his book, Greek Tragedy, published in 1939. In addition to his work on tragic drama here considered there appeared in print last year a small volume by him on Sophocles as dramatist and philosopher. In 1957 Harvard University published a long-awaited, monumental study of Aristotle's Poetics by Professor Gerald F. Else of the University of Michigan, and in 1958 The Johns Hopkins Press published in book form six lectures delivered in Baltimore by Professor Richmond Lattimore on The Poetry of Greek Tragedy. That these classical scholars should have, during recent years, made such varied contributions to an understanding of Greek tragedy — a field to which each of them has devoted a major portion of his academic life — is noteworthy but scarcely surprising, since the Greek theatre and the Greek tragedians have been a perennial subject in the history of classical philology.

Synthesis and Reactions of Alkenes

2015 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Stereoselective Synthesis ◽  
Rhodium Complex ◽  
University Of Wisconsin ◽  
Federal Institute ◽  
Institute Of Technology ◽  
La Jolla ◽  
University Of Bristol ◽  
The University ◽  
Academy Of Sciences ◽  
Trisubstituted Alkenes

Christine L. Willis and Varinder K. Aggarwal at the University of Bristol have developed (Angew. Chem. Int. Ed. 2012, 51, 12444) a procedure for the diastereodivergent synthesis of trisubstituted alkenes via the protodeboronation of allylic boronates, such as in the conversion of 1 to either 2 or 3. An alternative approach to the stereoselective synthesis of trisubstituted alkenes involving the reduction of the allylic C–O bond of cyclic allylic ethers (e.g., 4 to 5) was reported (Chem. Commun. 2012, 48, 7844) by Jon T. Njardarson at the University of Arizona. A novel synthesis of allylamines was developed (J. Am. Chem. Soc. 2012, 134, 20613) by Hanmin Huang at the Chinese Academy of Sciences with the Pd(II)-catalyzed vinylation of styrenes with aminals (e.g. 6 + 7 to 8). Eun Jin Cho at Hanyang University showed (J. Org. Chem. 2012, 77, 11383) that alkenes such as 9 could be trifluoromethylated with iodotrifluoromethane under visible light photoredox catalysis. David A. Nicewicz at the University of North Carolina at Chapel Hill developed (J. Am. Chem. Soc. 2012, 134, 18577) a photoredox procedure for the anti-Markovnikov hydroetherification of alkenols such as 11, using the acridinium salt 12 in the presence of phenylmalononitrile (13). A unique example of “catalysis through temporary intramolecularity” was reported (J. Am. Chem. Soc. 2012, 134, 16571) by André M. Beauchemin at the University of Ottawa with the formaldehyde-catalyzed Cope-type hydroamination of allyl amine 15 to produce the diamine 16. A free radical hydrofluorination of unactivated alkenes, including those bearing complex functionality such as 17, was developed (J. Am. Chem. Soc. 2012, 134, 13588) by Dale L. Boger at Scripps, La Jolla. Jennifer M. Schomaker at the University of Wisconsin at Madison reported (J. Am. Chem. Soc. 2012, 134, 16131) the copper-catalyzed conversion of bromostyrene 19 to 20 in what was termed an activating group recycling strategy. A rhodium complex 23 that incorporates a new chiral cyclopentadienyl ligand was developed (Science 2012, 338, 504) by Nicolai Cramer at the Swiss Federal Institute of Technology in Lausanne and was shown to promote the enantioselective merger of hydroxamic acid derivative 21 and styrene 22 to produce 24.

Stereocontrolled C-N Ring Construction: The Pyne Synthesis of Hyacinthacine B 3

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Chemistry ◽  
Conjugate Addition ◽  
Enantioselective Hydrogenation ◽  
Pd Catalyst ◽  
University Of Michigan ◽  
Palo Alto ◽  
University Of Toronto ◽  
University Of Oxford ◽  
University Of Bristol ◽  
The University

Keiji Maruoka of Kyoto University found (Organic Lett. 2010, 12, 1668) that the diazo amide 1 derived from the Oppolzer sultam condensed with the imine 2 to give the aziridine 3 with high stereocontrol. Andrei K. Yudin of the University of Toronto observed (Angew. Chem. Int. Ed. 2010, 49, 1607) that the unprotected aziridine aldehyde 4, which exists as a mixture of dimers, condensed smoothly with the Ohira reagent 5 to give the alkynyl aziridine 6. David M. Hodgson of the University of Oxford successfully (Angew. Chem. Int. Ed. 2010, 49, 2900) deprotonated the azetidine thioamide 7 to give, after allylation, the azetidine 8. Varinder K. Aggarwal of the University of Bristol devised (Chem. Commun. 2010, 267) a Pd catalyst for the cyclocarbonylation of an alkenyl aziridine 9 to give the β-lactam 10. Iain Coldham of the University of Sheffield used (J. Org. Chem. 2010, 75, 4069) the ligand they had developed to effect enantioselective allylation of the pyrrolidine derivative 11. The corrresponding piperidine worked as well. John P. Wolfe of the University of Michigan established (Organic Lett. 2010, 12, 2322) that the Pd-mediated cyclization of 13 to 15 could be effected with high diastereocontrol. Christopher G. Frost of the University of Bath optimized (Angew. Chem. Int. Ed. 2010, 49, 1825) the tandem Ru-mediated conjugate addition/cyclization of 16 to give 18 in high ee. Barry M. Trost of Stanford University extended (J. Am. Chem. Soc. 2010, 132, 8238) their studies of trimethylenemethane cycloaddition to the ketimine 19, leading to the substituted pyrrolidine 21 in high ee. Pher G. Andersson of Uppsala University optimized (J. Am. Chem. Soc. 2010, 132, 8880) an Ir catalyst for the enantioselective hydrogenation of readily prepared tetrahydropyridines such as 22. Min Shi of the Shanghai Institute of Organic Chemistry devised (J. Org. Chem. 2010, 75, 3935) a Pd catalyst for enantioselective conjugate addition to the prochiral pyridone 24. Xiaojun Huang of Roche Palo Alto prepared (Tetrahedron Lett. 2010, 51, 1554) the monoacid 26 by enantioselective methanolysis of the anhydride. Selective formylation of the ester led to the pyridone 27.

Enantioselective Construction of Arrays of Stereogenic Centers: The Breit Synthesis of (+)-Bourgeanic Acid

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Enantioselective Hydrogenation ◽  
Pt Catalyst ◽  
Dipolar Cycloaddition ◽  
Unsaturated Ester ◽  
Asymmetric Allylation ◽  
One Pot ◽  
University Of Texas ◽  
La Jolla ◽  
University Of Bristol ◽  
The University

Kyungsoo Oh of Indiana University Purdue University Indianapolis devised (Organic Lett. 2009, 11, 5682) a new ligand that with Cu delivered predominantly one diastereomer of the Henry adduct 3, and with Zn delivered the other. Liu-Zhu Gong of the University of Science and Technology of China reported (Angew. Chem. Int. Ed. 2009, 48, 6503) the Darzens condensation of the diazoacetamide 5 with a variety of aldehydes to give the corresponding epoxy amides with high diastereo- and enantiocontrol. Michael J. Krische of the University of Texas, Austin, applied (Organic Lett. 2009, 11, 3108, 3112) his asymmetric allylation to a variety of primary diols including 7, leading to the homologated product 9. M. Christina White of the University of Illinois showed (J. Am. Chem Soc. 2009, 131, 11707) that Pd-mediated oxidative amination of carbamate 10 delivered the protected 1,3-amino alcohol 11 with high diastereocontrol. James P. Morken of Boston College devised (J. Am. Chem Soc. 2009, 131, 9134) a Pt catalyst for the asymmetric bis-boration of dienes. The allyl borane prepared from 12 added with high stereocontrol to benzaldehyde, to give, after oxidation, the diol 13. Carlos F. Barba III of Scripps/La Jolla optimized (Angew. Chem. Int. Ed. 2009, 48, 9848) an organocatalyst for the enantioselective conjugate addition of an alkoxy aldehyde 15 to a nitroalkene. Do Hyun Ryu of Sungkyunkwan University found (Chem. Commun. 2009, 5460) that an organocatalyst could also mediate the dipolar cycloaddition of a diazo ester 18 to an unsaturated aldehyde, giving 19 with high diastereo- and enantiocontrol. Francesco Fini and Luca Bernardi of the University of Bologna developed (J. Am. Chem Soc. 2009, 131, 9614) an organocatalyst that effected enantioselective dipolar cycloaddition of the nitrone derived from 20 to the unsaturated ester 21. Kevin Burgess of Texas A&M optimized (J. Am. Chem Soc. 2009, 131, 13236) an Ir catalyst for the enantioselective hydrogenation of trisubstituted alkenes such as 23. In the course of a synthesis of (+)-faranal, Varinder K. Aggarwal of the University of Bristol described (Angew. Chem. Int. Ed. 2009, 48, 6317) a one-pot procedure for the conversion of the allyl borane 25 into 27.

Substituted Benzenes: The Alvarez- Manzaneda Synthesis of (–)-Akaol A

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Bond Formation ◽  
University Of Michigan ◽  
Aromatic Substitution ◽  
Substituted Benzenes ◽  
University Of Oklahoma ◽  
Meta Position ◽  
Substitution Chemistry ◽  
La Jolla ◽  
The University ◽  
École Polytechnique

Ramin Ghorbani-Vaghei of Bu-Ali Sina University devised (Tetrahedron Lett. 2012, 53, 2325) conditions for the bromination of an electron-deficient arene such as 1. Yonghong Gu of the University of Science and Technology of China found (Tetrahedron Lett. 2011, 52, 4324) that an electron-rich anilide 3 could be oxidized to 4. Sukbok Chang of KAIST (J. Am. Chem. Soc. 2012, 134, 2528) and Kouichi Ohe of Kyoto University (Chem. Commun. 2012, 48, 3127) devised protocols for the oxidative cyanation of 5 to 6. Phenylazocarboxylates and triazenes are stable, but have the reaction chemistry of diazonium salts. The aromatic substitution chemistry of these derivatives has not been much explored. As illustrated by the conversion of 7 to 8, reported (J. Org. Chem. 2012, 77, 1520) by Markus R. Heinrich of the Universität Erlangen-Nürnberg, the benzene ring of the phenylazocarboxylate is reactive with nucleophiles. In contrast, triazene-activated benzene rings should be particularly reactive with electrophiles, as exemplified by the transformation, below, of 20 to 21. Melanie S. Sanford of the University of Michigan observed (Org. Lett. 2012, 14, 1760) good selectivity for 12 in the Pd-catalyzed reaction of 10 with 11. Jérôme Waser of the Ecole Polytechnique Fédérale de Lausanne used (Org. Lett. 2012, 14, 744) 14 to alkynylate 13 to give 15. Sulfonyl chlorides such as 16 are readily prepared from the corresponding arene, and many are commercially available. Jiang Cheng of Wenzhou University found (Chem. Commun. 2012, 48, 449) conditions for the direct cyanation of 16 to 17. Kenneth M. Nicholas of the University of Oklahoma effected (J. Org. Chem. 2012, 77, 5600) selective ortho bromination of the carbamate 18 to give 19. Stefan Bräse of KIT observed (Angew. Chem. Int. Ed. 2012, 51, 3713) ortho trifluoromethylation of the triazene 20 to give 21. Ji-Quan Yu of Scripps/La Jolla designed (Nature 2012, 486, 518) the benzyl ether 22 to activate the arene for C–C bond formation at the meta position to give 23. Guo-Jun Deng of Xiangtan University employed (Org. Lett. 2012, 14, 1692) a borrowed hydrogen strategy to effect aromatization of 24 with nitrobenzene to give the aniline 25.

Substituted Benzenes: The Piers/Lau Synthesis of Hamigeran B

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
New York ◽  
Indian Institute ◽  
Ni Catalyst ◽  
State University ◽  
Vicarious Nucleophilic Substitution ◽  
City College ◽  
Institute Of Technology ◽  
La Jolla ◽  
University Of Bristol ◽  
The University

Govindasamy Sekar of the Indian Institute of Technology, Madras, developed ( Chem. Commun. 2011, 47, 5076) an environmentally friendly procedure for the amination of 1 to 2. Jens-Uwe Peters of Hoffmann-La Roche, Basel, showed (Tetrahedron Lett. 2011, 52, 749) that the Udenfriend protocol could be used to convert drugs such as 3 to their hydroxylated metabolites. Suman L. Jain and Anil K. Sinha of the Indian Institute of Petroleum reported (Chem. Commun. 2011, 47, 1610) complementary conditions for arene hydroxylation. Dimethyl aniline has been used, inter alia, as a nucleophile in enantioselective MacMillan conjugate addition. Zhong-Xia Wang of USTC established (Angew. Chem. Int. Ed. 2011, 50, 4901) that the quaternized salt 5 could participate in Negishi coupling. Mark R. Biscoe of the City College of New York discovered (Org. Lett. 2011, 13, 1218) that with a Ni catalyst, the secondary organozinc 9 will couple without rearrangement. Igor V. Alabugin of Florida State University devised (J. Org. Chem. 2011, 76, 1521) a radical-based protocol for replacing a phenolic OH with alkyl, to give 12. Petr Beier of the Academy of Sciences of the Czech Republic used (J. Org. Chem. 2011, 76, 4781) vicarious nucleophilic substitution followed by alkylation to convert 13 to 15. Robin B. Bedford of the University of Bristol developed (Angew. Chem. Int. Ed. 2011, 50, 5524) a Pd-catalyzed procedure for the ortho bromination of an anilide 16. Jin-Quan Yu of Scripps/La Jolla took advantage (J. Am. Chem. Soc. 2011, 133, 7652) of the energetic N-O bond of 19 to drive the functionalization of 18 to 20. Lei Liu of Tsinghua University devised (Org. Lett. 2011, 13, 3235) a Rh-mediated oxidative ortho coupling of the carbamate 21 with 22. Kohtaro Kirimura of Waseda University inserted (Chem. Lett. 2011, 40 , 206) the DNA for a novel Trichosporon decarboxylase into Escherichia coli and found that the resulting fermentation efficiently converted 24 into 25. The alternative Kolbe-Schmitt reaction requires high temperature and pressure. Sometimes, usually with more highly substituted benzene rings, creating the ring is worthwhile.

Organocatalyzed C–C Ring Construction: The Jørgenson Synthesis of (+)-Estrone

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
New England ◽  
Hydroxy Ketone ◽  
Ethyl Vinyl Ether ◽  
State University ◽  
Ethyl Vinyl ◽  
National University ◽  
North Dakota State University ◽  
Indian Institute Of Science ◽  
The University ◽  
Pais Vasco

Ana Maria Faísca Phillips and Maria Teresa Barros of the Universidade Nova de Lisboa added (Eur. J. Org. Chem. 2014, 152) the bromo ester 1 to cinnamaldehyde 2 to give the cyclopropyl phosphonate 3 in high ee. Mukund P. Sibi and Jayaraman Sivaguru of North Dakota State University used (Angew. Chem. Int. Ed. 2014, 53, 5604) an organocatalyst to mediate the 2+2 photocycloaddition of 4, leading to 5. Shu-Li You of the Shanghai Institute of Organic Chemistry expanded (Org. Lett. 2014, 16, 1810) the four-membered ring of 6 to create the cyclopentanone 7 in high ee. Damien Bonne and Jean Rodriguez of Aix-Marseille Université condensed (Chem. Eur. J. 2014, 20, 410) the cyclopentanone 8 with 9 to give 10. Santanu Mukherjee of the Indian Institute of Science, Bangalore added (Chem. Sci. 2014, 5, 1627) the lac­tone 12 to the prochiral 11 to give 13 with remarkable diastereo- and enantiocontrol. Yixin Lu of the National University of Singapore constructed (Angew. Chem. Int. Ed. 2014, 53, 5643) the cyclopentene 16 by adding 14 to the allene 15. Efraim Reyes and Jose L. Vicario of the Universidad del País Vasco prepared (Chem. Eur. J. 2014, 20, 2145) the highly substituted cyclohexene 19 by combining 17 and 18. Maurizio Benaglia of the Università degli Studi di Milano added (Adv. Synth Catal. 2014, 356, 493) the ketone 20 to 21 to create the cyclohexanone 22. Ben W. Greatrex of the University of New England in Australia used (J. Org. Chem. 2014, 79, 5088) an organocatalyst to cyclize the symmetrical dialdehyde 23 to the α-hydroxy ketone 24. Dieter Enders of RWTH Aachen added (Org. Lett. 2014, 16, 2954) the β-keto ester 25 to 26 to give an intermediate that was further condensed with 27 to complete the preparation of 28. Eric N. Jacobsen of Harvard University prepared (Angew. Chem. Int. Ed. 2014, 53, 5912) the cycloheptenone 30 by the enantioselective intermolecular addition of the pyrylium salt derived from 29 to ethyl vinyl ether. Bor-Cherng Hong of the National Chung Cheng University initiated (Org. Lett. 2014, 16, 2724) the assembly of the steroid derivative 33 by the enantioselective addition of 32 to the unsaturated aldehyde 31.

Sign in / Sign up

Export Citation Format

Share Document