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.

Metal-Mediated Carbocyclic Construction: The Simpkins Synthesis of Ialibinones A and B

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Gold Catalyst ◽  
Conjugate Addition ◽  
South Florida ◽  
Pt Catalyst ◽  
General Strategy ◽  
Ru Catalyst ◽  
University Of Technology ◽  
Rh Catalyst ◽  
Institute Of Technology ◽  
The University

Adriaan J. Minnaard and Ben L. Feringa of the University of Groningen devised (J. Am. Chem. Soc. 2010, 132, 14349) what promises to be a general strategy for the construction of enantiomerically pure cyclopropanes, based on conjugate addition to acceptors such as 1 . X. Peter Zhang of the University of South Florida developed (J. Am. Chem. Soc. 2010, 132, 12796) a Co catalyst for the enantioselective cyclopropanation of α-olefins such as 3. Seiji Iwasa of Toyohashi University of Technology designed (Angew. Chem. Int. Ed. 2010, 49, 8439) a resin-bound Ru catalyst that could be used repeatedly for the enantioselective cyclization of the ester 6. Rai-Shung Lin of National Tsing-Hua University showed (Angew. Chem. Int. Ed. 2010, 49, 9891) that a gold catalyst could expand the alkyne 8 to the cyclobutene 9. Takao Ikariya of the Tokyo Institute of Technology reported (J. Am. Chem. Soc. 2010, 132, 16637) a detailed study of the enantioselective conjugate addition of malonate 11 to cyclopentenone 10. Vladimir A. D’yakonov of the Russian Academy of Sciences, Ufa, showed (Tetrahedron Lett. 2010, 51, 5886) that a cyclic alkyne 13 could be annulated to the cyclopentenone 14. Shunichi Hashimoto of Hokkaido University also designed (Angew. Chem. Int. Ed. 2010, 49, 6979) a resin-bound Rh catalyst that could also be used repeatedly for the enantioselective cyclization of the ester 15. Tushar Kanti Chakraborty of the Central Drug Research Institute used (Tetrahedron Lett. 2010, 51, 4425) Ti(III) to mediate the diastereoselective cyclization of 17 to 18. Alexandre Alexakis of the University of Geneva extended (Synlett 2010, 1694) enantioselective conjugate addition of isopropenyl to the more difficult enone 19. Joseph P. A. Harrity of the University of Sheffield showed (Org. Lett. 2010, 12, 4832) that Pd could catalyze the rearrangement of 21 to 22. Strategies for the controlled construction of polycyclic ring systems are also important. Günter Helmchen of the Universität Heidelberg showed (J. Org. Chem. 2010, 75, 7917) that 23 was efficiently cyclized to the diene with Pt catalyst. The reaction could be carried out in the presence of the dienophile 24 to give 25 directly.

Organic Functional Group Interconversion

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Reduced Form ◽  
Ni Catalyst ◽  
Max Planck ◽  
University Of Maryland ◽  
Ru Catalyst ◽  
Maryland School ◽  
National University ◽  
Rh Catalyst ◽  
Seoul National University ◽  
The University

Alois Fürstner of the Max-Planck-Institut Mülheim devised (Angew. Chem. Int. Ed. 2013, 52, 14050) a Ru catalyst for the trans- selective hydroboration of an alkyne 1 to 2. Qingbin Liu of Hebei Normal University and Chanjuan Xi of Tsinghua University coupled (Org. Lett. 2013, 15, 5174) the alkenyl zirconocene derived from 3 with an acyl azide to give the amide 4. Chulbom Lee of Seoul National University used (Angew. Chem. Int. Ed. 2013, 52, 10023) a Rh catalyst to convert a terminal alkyne 5 to the ester 6. Laura L. Anderson of the University of Illinois, Chicago devised (Org. Lett. 2013, 15, 4830) a protocol for the conversion of a ter­minal alkyne 7 to the α-amino aldehyde 9. Dewen Dong of the Changchun Institute of Applied Chemistry developed (J. Org. Chem. 2013, 78, 11956) conditions for the monohydrolysis of a bis nitrile 10 to the monoamide 11. Aiwen Lei of Wuhan University optimized (Chem. Commun. 2013, 49, 7923) a Ni catalyst for the conversion of the alkene 12 to the enamide 13. Kazushi Mashima of Osaka University optimized (Adv. Synth. Catal. 2013, 355, 3391) a boronic ester catalyst for the conversion of an amide 14 to the ester 15. Jean- François Paquin of the Université Laval prepared (Eur. J. Org. Chem. 2013, 4325) the amide 17 by coupling an amine with the activated intermediate from reaction of an acid 16 with Xtal- Fluor E. Steven Fletcher of the University of Maryland School of Pharmacy designed (Tetrahedron Lett. 2013, 54, 4624) the azodicarbonyl dimorpholide 18 as a reagent for the Mitsunobu coupling of 19 with 20. The reduced form of 18 was readily separated by extraction into water and reoxidized. Jens Deutsch of the Universität Rostock found (Chem. Eur. J. 2013, 19, 17702) simple ligands for the Ru-mediated borrowed hydro­gen conversion of an alcohol 22 to the amine 23. Ronald T. Raines of the University of Wisconsin devised (J. Am. Chem. Soc. 2013, 135, 14936) a phosphinoester for the efficient conversion in water of an azide 24 to the diazo 25.

C–H Functionalization

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Oxidative Cyclization ◽  
South Florida ◽  
Hypervalent Iodine ◽  
Direct Oxidation ◽  
University Of Texas ◽  
Ru Catalyst ◽  
University Of Technology ◽  
National University ◽  
Indian Institute Of Science ◽  
The University

Masayuki Inoue of the University of Tokyo oxidized (Tetrahedron Lett. 2011, 52, 4654) the alkyl benzene 1 to the nitrate 2, which could be carried on to the amide 5, the nitrile 6, the alcohol 7, or the azide 8. X. Peter Zhang of the University of South Florida developed (Chem. Sci. 2012, 2, 2361) a Co catalyst for the cyclization of 7 to 8. Justin Du Bois of Stanford University reported (J. Am. Chem. Soc. 2011, 133, 17207) the oxidative cyclization of the sulfamate corresponding to 7 using a Ru catalyst. Seongmin Lee of the University of Texas showed (Org. Lett. 2011, 13, 4766) that the oxidative cyclization of 9 gave the amine 10 with high diastereoselectivity. Fabrizio Fabris of the Università di Venezia used (Tetrahedron Lett. 2011, 52, 4478) a Ru catalyst to oxidize 11 to the ketone 12. Ying-Yeung Yeung of the National University of Singapore found (Org. Lett. 2011, 13, 4308) that hypervalent iodine was sufficient to oxidize 13 to the ketone 14. Huanfeng Jiang of the South China University of Technology methoxycarbonylated (Chem. Commun. 2011, 47, 12224) 15 under Pd catalysis to give 16. Professor Inoue found (Org. Lett. 2011, 13, 5928) that the oxidative cyanation of 17 proceeded with high diastereoselectivity to give 18. Mamoru Tobisu and Naoto Chatani of Osaka University activated (J. Am. Chem. Soc. 2011, 133, 12984) 19 with a Pd catalyst to enable coupling with 20 to give 21. Rh-mediated intramolecular insertion is well known to proceed efficiently into secondary and tertiary C–H bonds. A. Srikrishna of the Indian Institute of Science, Bangalore found (Synlett 2011, 2343) that insertion into the methyl C–H of 22 also worked smoothly to deliver 23. The macrocyclic oligopeptide valinomycin 24 has nine isopropyl groups. It is remarkable, as observed (Org. Lett. 2011, 13, 5096) by Cosimo Annese of the Università di Bari and Paul G. Williard of Brown University, that direct oxidation of 24 with methyl(trifluoromethyl) dioxirane in acetone specifically hydroxylated at 8 (45.5%, our numbering), 7 (28.5%), and 6 (26%).

Functionalization and Homologation of C-H Bonds

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Crop Protection ◽  
Oxidative Cyclization ◽  
South Florida ◽  
State University ◽  
Ru Catalyst ◽  
University Of Oklahoma ◽  
Princeton University ◽  
La Jolla ◽  
The University ◽  
Technological University

Justin Du Bois of Stanford University developed (J. Am. Chem. Soc. 2010, 132, 10202) a Ru catalyst for the stereoretentive hydroxylation of 1 to 2. John T. Groves of Princeton University effected (J. Am. Chem. Soc. 2010, 132, 12847) equatorial chlorination of the test substrate 3. Kenneth M. Nicholas of the University of Oklahoma found (J. Org. Chem. 2010, 75, 7644) that I2 catalyzed the amination of 5. Thorsten Bach of the Technische Universität München established (Org. Lett. 2010, 12, 3690) that the amination of 7 proceeded with significant diastereoselectivity. Phil S. Baran of Scripps/La Jolla compiled (Synlett 2010, 1733) an overview of the development of C-H oxidation. Tethering can improve the selectivity of C-H functionalization. X. Peter Zhang of the University of South Florida devised (Angew. Chem. Int. Ed. 2010, 49, 10192) a Co catalyst for the cyclization of 9 to 10. Teck-Peng Loh of Nanyang Technological University established (Angew. Chem. Int. Ed. 2010, 49, 8417) conditions for the oxidation of 11 to 12. Jin-Quan Yu, also of Scripps/La Jolla, effected (J. Am. Chem. Soc. 2010, 132, 17378) carbonylation of methyl C-H of 13 to give 14. Sunggak Kim, now also at Nanyang Technological University, established (Synlett 2010, 1647) conditions for the free-radical homologation of 15 to 17. Gong Chen of Pennsylvania State University extended (Org. Lett. 2010, 12, 3414) his work on remote Pd-mediated activation by cyclizing 18 to 19. Many schemes have been developed in recent years for the oxidation of substrates to reactive electrophiles. Gonghua Song of the East China University of Science and Technology and Chao-Jun Li of McGill University reported (Synlett 2010, 2002) Fe nanoparticles for the oxidative coupling of 20 with 21. Zhi-Zhen Huang of Nanjing University found (Org. Lett. 2010, 12, 5214) that protonated pyrrolidine 25 was important for mediating the site-selective coupling of 24 with 23. Y. Venkateswarlu of the Indian Institute of Chemical Technology, Hyderabad, was even able (Tetrahedron Lett. 2010, 51, 4898) to effect coupling with a cyclic alkene 28. AB3217-A 32, isolated in 1992, was shown to have marked activity against two spotted spider mites. Christopher R. A. Godfrey of Syngenta Crop Protection, Münchwilen, prepared (Synlett 2010, 2721) 32 from commercial anisomycin 30a. The key step in the synthesis was the oxidative cyclization of 30b to 31.

Organocatalyzed C–C Ring Construction: The Mihovilovic Synthesis of Piperenol B

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
State University ◽  
Air Oxidation ◽  
Microbial Oxidation ◽  
Max Planck ◽  
National Chemical Laboratory ◽  
Chemical Laboratory ◽  
Northwestern University ◽  
National University ◽  
The University ◽  
Oregon State University

M. Kevin Brown of Indiana University prepared (J. Am. Chem. Soc. 2015, 137, 3482) the cyclobutane 3 by the organocatalyzed addition of 2 to the alkene 1. Karl Anker Jørgensen of Aarhus University assembled (J. Am. Chem. Soc. 2015, 137, 1685) the complex cyclobutane 7 by the addition of 5 to the acceptor 4, followed by conden­sation with the phosphorane 6. Zhi Li of the National University of Singapore balanced (ACS Catal. 2015, 5, 51) three enzymes to effect enantioselective opening of the epoxide 8 followed by air oxidation to 9. Gang Zhao of the Shanghai Institute of Organic Chemistry and Zhong Li of the East China University of Science and Technology added (Org. Lett. 2015, 17, 688) 10 to 11 to give 12 in high ee. Akkattu T. Biju of the National Chemical Laboratory combined (Chem. Commun. 2015, 51, 9559) 13 with 14 to give the β-lactone 15. Paul Ha-Yeon Cheong of Oregon State University and Karl A. Scheidt of Northwestern University reported (Chem. Commun. 2015, 51, 2690) related results. Dieter Enders of RWTH Aachen University constructed (Chem. Eur. J. 2015, 21, 1004) the complex cyclopentane 20 by the controlled com­bination of 16, 17, and 18, followed by addition of the phosphorane 19. Derek R. Boyd and Paul J. Stevenson of Queen’s University Belfast showed (J. Org. Chem. 2015, 80, 3429) that the product from the microbial oxidation of 21 could be protected as the acetonide 22. Ignacio Carrera of the Universidad de la República described (Org. Lett. 2015, 17, 684) the related oxidation of benzyl azide (not illustrated). Manfred T. Reetz of the Max-Planck-Institut für Kohlenforschung and the Philipps-Universität Marburg found (Angew. Chem. Int. Ed. 2014, 53, 8659) that cytochrome P450 could oxidize the cyclohexane 23 to the cyclohexanol 24. F. Dean Toste of the University of California, Berkeley aminated (J. Am. Chem. Soc. 2015, 137, 3205) the ketone 25 with 26 to give 27. Benjamin List, also of the Max-Planck-Institut für Kohlenforschung, reported (Synlett 2015, 26, 1413) a parallel investigation. Philip Kraft of Givaudan Schweiz AG and Professor List added (Angew. Chem. Int. Ed. 2015, 54, 1960) 28 to 29 to give 30 in high ee.

C–O Ring Construction: The Oger/Lee/Galano Synthesis of 7(RS)-ST-Δ8-11-dihomo-Isofuran

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Ring Expansion ◽  
Radical Mechanism ◽  
Columbia University ◽  
University Of Michigan ◽  
Max Planck ◽  
University Of British Columbia ◽  
University Of Technology ◽  
National University ◽  
Seoul National University ◽  
The University

Shaorong Yang and Huanfeng Jiang of the South China University of Technology assembled (Angew. Chem. Int. Ed. 2014, 53, 7219) the β-lactone 3 by the Pd-catalyzed addition of 2 to the alkyne 1. Jack R. Norton of Columbia University observed (J. Am. Chem. Soc. 2015, 137, 1036) that the vanadium-mediated reduc­tive cyclization of 4 proceeded by a free radical mechanism, leading to the cis 3,4-disubstituted tetrahydrofuran 5. The cyclization of 6 to 7 developed (J. Org. Chem. 2015, 80, 965) by Glenn M. Sammis of the University of British Columbia also involved H atom transfer. Amy R. Howell of the University of Connecticut devised (J. Org. Chem. 2015, 80, 5196) the ring expansion of the β-lactone 8 to the tet­rahydrofuran 9. Dmitri V. Filippov and Jeroen D. C. Codée of Leiden University showed (J. Org. Chem. 2015, 80, 4553) that the net reductive alkylation of the lac­tone 10 led to 11 with high diastereocontrol. A. Stephen K. Hashmi of the Ruprecht-Karls-Universität Heidelberg optimized (Chem. Eur. J. 2015, 21, 427) the gold-mediated rearrangement of the ester 12 to the lactone 13. This reaction apparently proceeded by the coupling of the metalated lac­tone with a propargylic carbocationic species. Benjamin List of the Max-Planck-Institut für Kohlenforschung developed (Angew. Chem. Int. Ed. 2015, 54, 7703) an organocatalyst that mediated the addition of 15 to 14, leading to 16 in high ee. Scott E. Denmark of the University of Illinois published (Nature Chem. 2015, 6, 1056) a detailed study of the enantioselective cyclization of 17 to 18. Shunichi Hashimoto of Hokkaido University established (Tetrahedron Lett. 2015, 56, 1397) that his catalyst was effective for the cycli­zation of 19 to 20. Debendra K. Mohapatra of the Indian Institute of Chemical Technology showed (J. Org. Chem. 2015, 80, 1365) that allyl trimethylsilane could trap the intermediate from the cyclization of 21, leading to 22 with high diastereocontrol. Young-Ger Suh of Seoul National University used (Chem. Commun. 2015, 51, 9026) a Pd catalyst to cyclize 23 to (−)-deguelin 24. John Montgomery of the University of Michigan showed (Org. Lett. 2015, 17, 1493) that the Ni-catalyzed reduc­tive cyclization of 25 to 26 proceeded with high diastereoselectivity.

scholarly journals Review of the Theories of Critical Thinking. An Approach Directed to the Professional Career of Medical Technology of the National University of Jaén in Peru

2021 ◽  
pp. 11-21
Author(s):  
José Paredes Carranza
Keyword(s):  
Critical Thinking ◽  
Medical Technology ◽  
Health Science ◽  
Educational Quality ◽  
Main Criterion ◽  
University Environment ◽  
Professional Career ◽  
National University ◽  
The University ◽  
Theoretical Foundations

The development of Critical Thinking is recognized as the main criterion of educational quality in international forums of Higher Education. However, there are few studies on the teaching processes, skills and methods to meet this criterion in Peruvian universities. This paper presents a review of the different approaches to critical thinking with an emphasis on students of the medical technology career at the National University of Jaén. The theoretical foundations of critical thinking are addressed, it is contextualized in the careers of health science, it is linked to scientific production and reasoning and the university environment from the various perspectives of critical thinking with an emphasis on university students. All this in order to present critical thinking in the daily dynamics of students of the medical technology career at the National University of Jaén, Peru.

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.

C–O Ring-Containing Natural Products: (+)-Isatisine A (Panek), Cephalasporolide E (Sartillo-Piscil), (+)-Xestodecalactone ( Jennings), Colchilomycin B (Banwell), Lactimidomycin (Georg), 5,6-Dihydrocineromycin B (Fürstner)

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Marine Fungus ◽  
Alkyne Metathesis ◽  
University Of Alabama ◽  
University Of Minnesota ◽  
Max Planck ◽  
80S Ribosome ◽  
Boston University ◽  
National University ◽  
The University ◽  
Trisubstituted Alkenes

(+)-Isatisine A 4 was isolated from Isatis indigotica, long used in traditional Asian medicine for the treatment of viral diseases. James S. Panek of Boston University set the stage (J. Org. Chem. 2015, 80, 2959) for the synthesis of 4 by the addition of the allyl silane 2 to the aldehyde 1 to give the highly substituted tetrahydrofuran 3. Fernando Sartillo- Piscil of Benemérita Universidad Autónoma de Puebla devised (J. Org. Chem. 2015, 80, 2601) an H-atom abstraction/fragmentation/cyclization cascade that converted 5 into the spiroketal cephalosporolide E 7. Cephalosporolide F, the unstable kinetic product from the cyclization, could be observed in the NMR spectrum of the crude product when a base was added. (+)-Xestodecalactone A 10 was isolated from the fungus Pencillium cf. mon­tanese, that was secured from the marine sponge Xestospongia exigua. Michael P. Jennings of the University of Alabama constructed (Eur. J. Org. Chem. 2015, 3303) the macrolactone of 10 by cyclizing the carboxylic acid 8 to 9 under Friedel-Crafts conditions. Colchilomycin B 13, isolated (without acetone!) from the marine fungus Cochliobolus lunatus, is a naturally occurring acetonide. Martin G. Banwell of the Australian National University showed (J. Org. Chem. 2015, 80, 460) that the Nozaki–Hiyama–Kishi cyclization of 11 to 12 proceeded with high diastereoselectivity. Lactimidomycin 16 binds to and so blocks the tRNA E-site of the 80S ribosome. Gunda I. Georg of the University of Minnesota assembled (Chem. Commun. 2015, 51, 8634) the macrolide triene of 16 by the cyclization of 14 to 15. Alois Fürstner of the Max-Planck-Institut für Kohlenforschung, who developed effective catalysts for alkyne metathesis, has been exploring (Angew. Chem. Int. Ed. 2015, 54, 6241) the conversion of the product cyclic alkynes to trisubstituted alkenes. In the synthesis of 5,6-dihydrocineromycin B 19, he took advantage of the directing propargylic alcohol for the conversion of 17 to 18.

Benzene Derivatives: The Tanino-Miyashita Synthesis of Zoanthenol

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Benzoic Acid ◽  
University Of Pennsylvania ◽  
University Of Southern California ◽  
Aryl Chlorides ◽  
National University ◽  
Rh Catalyst ◽  
Nitro Aromatics ◽  
La Jolla ◽  
University Of Oslo ◽  
The University

Yuqing Hou of Southern Illinois University found (J. Org. Chem. 2009, 74, 6362) that the peroxy ether 2 served effectively to directly transfer a methoxy group to the lithiated 1 to give 3. Wanzhi Chen of Zhejiang University, Xixi Campus, showed (J. Org. Chem. 2009, 74, 7203) that pyrimidines such as 4, readily prepared from the corresponding phenol, underwent smooth Pd-catalyzed ortho acetoxylation. Trond Vidar Hansen of the University of Oslo observed (Tetrahedron Lett. 2009, 50, 6339) that simple electrophilic formylation of phenols such as 6 also proceeded with high ortho selectivity. Kyung Woon Jung of the University of Southern California optimized (J. Org. Chem. 2009, 74, 6231) the Rh catalyst for ortho C-H insertion, converting 8 into 9. Jin-Quan Yu of Scripps/La Jolla devised (Science 2010, 327, 315) a protocol for carboxy-directed catalytic ortho palladation that allowed subsequent Heck coupling, transforming 10 into 11. Norikazu Miyoshi of the University of Tokushima established (Chem. Lett. 2009, 38, 996) that in situ generated strontium alkyls added 1,6 to benzoic acid 13, to give, after mild oxidative workup, the 4-alkyl benzoic acid 15. Amin Zarei of Islamic Azad University showed (Tetrahedron Lett. 2009, 50, 4443) that their previously developed protocol for preparing stable diazonium silica sulfates could be extended to the preparation of an aryl azide such as 17. Stephen L. Buchwald of MIT developed (J. Am. Chem. Soc. 2009, 131, 12898) a Pd-mediated protocol for the conversion of aryl chlorides to the corresponding nitro aromatics. Virgil Percec of the University of Pennsylvania has also reported (Organic Lett. 2009, 11, 4974) the conversion of an aryl chloride to the borane, and Guy C. Lloyd-Jones has described (Angew. Chem. Int. Ed. 2009, 48, 7612) the conversion of phenols to the corresponding thiols. Kwang Ho Song of Korea University and Sunwoo Lee of Chonnam National University demonstrated (J. Org. Chem. 2009, 74, 6358) that the Ni-mediated homologation of aryl halides worked with a variety of primary and secondary formamides. Kwangyong Park of Chung-Ang University observed (J. Org. Chem. 2009, 74, 9566) that Ni catalysts also mediated the coupling of Grignard reagents with the tosylate 22 not in the usual way but with the C-S bond to give 23.

Sign in / Sign up

Export Citation Format

Share Document