Heteroaromatic Construction: The Fukuyama Synthesis of Tryprostatin A

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Chemistry ◽  
University Of California ◽  
University Of Arkansas ◽  
Yale University ◽  
Au Catalyst ◽  
University Of Houston ◽  
Selective Substitution ◽  
Mcgill University ◽  
La Jolla ◽  
The University

Alessandro Palmieri of the University of Camerino developed (Synlett 2010, 2468) the condensation of a nitro acrylate 1 with a 1,3-dicarbonyl partner 2 to give the furan 3. Chaozhong Li of the Shanghai Institute of Organic Chemistry showed (Tetrahedron Lett. 2010, 51, 3678) that an alkenyl halide 4 could be cyclized to the furan 5. Ayhan S. Demir of Middle East Technical University established (Chem. Commun. 2010, 46, 8032) that a Au catalyst could catalyze the addition of an amine 7 to a cyanoester 6 to give the pyrrole 8 . Bruce A. Arndtsen of McGill University effected (Org. Lett. 2010, 12, 4916) the net three-component coupling of an imine 9, an acid chloride 10, and an alkyne 11 to deliver the pyrrole 12. Bernard Delpech of CNRS Gif-sur-Yvette prepared (Org. Lett. 2010, 12, 4760) the pyridine 15 by combining the diene 13 with the incipient carbocation 14. Max Malacria, Vincent Gandon, and Corinne Aubert of UPMC Paris optimized (Synlett 2010, 2314) the internal Co-mediated cyclization of a nitrile alkyne 5 to the tetrasubstituted pyridine 17. Yoshiaki Nakao of Kyoto University and Tamejiro Hiyama, now at Chuo University, effected (J. Am. Chem. Soc. 2010, 132, 13666) selective substitution of a preformed pyridine 18 at the C-4 position by coupling with an alkene 19. We showed (J. Org. Chem. 2010, 75, 5737) that the anion from deprotonation of a pyridine 21 could be added in a conjugate sense to 22 to give 23. Other particularly useful strategies for further substitution of preformed pyridines have been described by Olafs Daugulis of the University of Houston (Org. Lett. 2010, 12, 4277), by Phil S. Baran of Scripps/La Jolla (J. Am. Chem. Soc. 2010, 132, 13194), and by Robert G. Bergmann of the University of California, Berkeley, and Jonathan A. Ellman of Yale University (J. Org. Chem. 2010, 75, 7863). K. C. Majumdar of the University of Kalyani developed (Tetrahedron Lett. 2010, 51, 3807) the oxidative Pd-catalyzed cylization of 24 to the indole 25. Nan Zheng of the University of Arkansas showed (Org. Lett. 2010, 12, 3736) that Fe could be used to catalyze the rearrangement of the azirine 26 to the indole 27.

C–H Functionalization: The Hatakeyama Synthesis of (–)-Kaitocephalin

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
University Of California ◽  
University Of Delaware ◽  
State University ◽  
Max Planck ◽  
Pennsylvania State University ◽  
University Of Illinois ◽  
University Of Houston ◽  
Hydride Abstraction ◽  
La Jolla ◽  
The University

John F. Hartwig of the University of California, Berkeley showed (Nature 2012, 483, 70) that intramolecular C–H silylation of 1 selectively gave, after oxidation and acetylation, the bis acetate 2. Gong Chen of Pennsylvania State University coupled (J. Am. Chem. Soc. 2012, 134, 7313) 3 with 4 to give the ether 5. M. Christina White of the University of Illinois effected (J. Am. Chem. Soc. 2012, 134, 9721) selective oxidation of the taxane derivative 6 to the lactone 7. Most of the work on C–H functionalization has focused on the formation of C–C, C–O, and C–N bonds. Donald A. Watson of the University of Delaware developed (Angew. Chem. Int. Ed. 2012, 51, 3663) conditions for the complementary conversion of an alkene 8 to the allyl silane 9, a powerful and versatile nucleophile. Kilian Muniz of ICIQ Tarragona oxidized (J. Am. Chem. Soc. 2012, 134, 7242) the enyne 10 selectively to the amine 11. Phil S. Baran of Scripps/La Jolla devised (J. Am. Chem. Soc. 2012, 134, 2547) a protocol for the OH-directed amination of 12 to 13. Professor White developed (J. Am. Chem. Soc. 2012, 134, 2036) a related OH-directed amination of 14 to 15 that proceeded with retention of absolute configuration. Tom G. Driver of the University of Illinois, Chicago showed (J. Am. Chem. Soc. 2012, 134, 7262) that the aryl azide 16 could be cyclized directly to the amine, which was protected to give 17. As illustrated by the conversion of 18 to 20 devised (Adv. Synth. Catal. 2012, 354, 701) by Martin Klussmann of the Max-Planck-Institut, Mülheim, C–H functionalization can be accomplished by hydride abstraction followed by coupling of the resulting carbocation with a nucleophile. Olafs Daugulis of the University of Houston used (Angew. Chem. Int. Ed. 2012, 51, 5188) a Pd catalyst to couple 21 with 22 to give 23 with high diastereocontrol. Yoshiji Takemoto of Kyoto University cyclized (Angew. Chem. Int. Ed. 2012, 51, 2763) the chloroformate 24 directly to the oxindole 25.

Synthesis of Substituted Benzenes: The Carter Synthesis of Siamenol

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Aryl Halides ◽  
Substituted Benzenes ◽  
Diversity Oriented Synthesis ◽  
University Of Illinois ◽  
University Of Houston ◽  
Direct Functionalization ◽  
University Of Edinburgh ◽  
Aryl Tosylates ◽  
La Jolla ◽  
The University

Tosylates are among the least expensive, but also among the least reactive toward Pd(0) oxidative addition, of aryl sulfonates. Jie Wu of Fudan University has now devised conditions (J. Org. Chem. 2007, 72, 9346) for the Pd-catalyzed coupling of aryl tosylates such as 1 with arene trifluoroborates. Kei Manabe of RIKEN has found (Organic Lett. 2007, 9, 5593) that an ortho OH activates an adjacent Cl for Pd-mediated coupling, allowing the conversion of 4 to 6 . Philippe Uriac and Pierre van de Weghe of the Université de Rennes I have developed (Organic Lett. 2007, 9, 3623) conditions for the catalytic acylation of aryl halides with alkenyl acetates such as 8. Multi-component coupling lends itself well to diversity-oriented synthesis. As illustrated by the combination of 10 with 11 and 12 to give 13 reported (Organic Lett. 2007, 9, 5589) by Michael F. Greaney of the University of Edinburgh, benzynes can do double addition with high regiocontrol. For other recent references to unsymmetrical double additions to arynes, see Angew.Chem. Int. Ed. 2007, 46, 5921; Chem. Commun. 2007, 2405; and J. Am. Chem. Soc. 2006, 128, 14042. C-H functionalization of arenes is of increasing importance. John F. Hartwig of the University of Illinois has described (Organic Lett. 2007, 9, 757; 761) improved conditions for Ir-catalyzed meta borylation, and conditions for further coupling of the initial borate 16 to give amines such as 17. Lei Liu and Qing-Xiang Guo of the University of Science and Technology, Hefei have found (Tetrahedron Lett. 2007, 48, 5449) that oxygen can be used as the stoichiometric oxidant in the Pd-catalyzed functionalization of H’s ortho to anilides. Two other research groups (J. Am. Chem. Soc. 2007, 129, 6066; Angew. Chem. Int. Ed. 2007, 46, 5554; J. Org. Chem. 2007, 72, 7720) reported advances in this area. In a close competition, Jin-Quan Yu, now at Scripps/La Jolla (J. Am. Chem. Soc. 2007, 129, 3510) and Olafs Daugulis of the University of Houston (J. Am. Chem. Soc. 2007, 129, 9879) both reported that a carboxyl group can activate an ortho H for direct functionalization.

Oxidation and Reduction

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Aryl Halide ◽  
Direct Reduction ◽  
University Of California ◽  
Yale University ◽  
University Of Pittsburgh ◽  
Ru Catalyst ◽  
Efficient Reduction ◽  
Radical Reduction ◽  
The University ◽  
Mediated Reduction

Kiyotomi Kaneda of Osaka University devised (Angew. Chem. Int. Ed. 2010, 49, 5545) gold nanoparticles that efficiently deoxygenated an epoxide 1 to the alkene 2. Robert G. Bergman of the University of California, Berkeley, and Jonathan A. Ellman, now of Yale University, reported (J. Am. Chem. Soc. 2010, 132, 11408) a related protocol for deoxygenating 1,2-diols. Dennis A. Dougherty of Caltech established (Org. Lett. 2010, 12, 3990) that an acid chloride 3 could be reduced to the phosphonate 4. Pei-Qiang Huang of Xiamen University effected (Synlett 2010, 1829) reduction of an amide 5 by activation with Tf2O followed by reduction with NaBH4. André B. Charette of the Université de Montreal described (J. Am. Chem. Soc. 2010, 132, 12817) parallel results with Tf2O/Et3SiH. David Milstein of the Weizmann Institute of Science devised (J. Am. Chem. Soc. 2010, 132, 16756) a Ru catalyst for the alternative reduction of an amide 7 to the amine 8 and the alcohol 9. Shi-Kai Tian of the University of Science and Technology of China effected (Chem. Commun. 2010, 46, 6180) reduction of a benzylic sulfonamide 10 to the hydrocarbon 11. Thirty years ago, S. Yamamura of Nagoya University reported (Chem. Commun. 1967, 1049) the efficient reduction of a ketone to the corresponding methylene with Zn/HCl. Hirokazu Arimoto of Tohoku University established (Tetrahedron Lett. 2010, 51, 4534) that a modified Zn/TMSCl protocol could be used following ozonolysis to effect conversion of an alkene 12 to the methylene 13. José Barluenga and Carlos Valdés of the Universidad de Oviedo effected (Angew. Chem. Int. Ed. 2010, 49, 4993) reduction of a ketone to the ether 16 by way of the tosylhydrazone 14. Kyoko Nozaki and Makoto Yamashita of the University of Tokyo and Dennis P. Curran of the University of Pittsburgh found (J. Am. Chem. Soc. 2010, 132, 11449) that the hydride 18 (actually a complex dimer) could effect the direct reduction of a halide 17 and also function as the hydrogen atom donor for free radical reduction and as the hydride donor for the Pd-mediated reduction of an aryl halide.

Book Reviews

2011 ◽  
Vol 49 (3) ◽  
pp. 776-777
Keyword(s):  
Los Angeles ◽  
Urban Life ◽  
University Of California ◽  
Yale University ◽  
Quality Of Urban Life ◽  
The University ◽  
The Hill ◽  
China’S Cities

Matthew J. Kotchen of Yale University reviews “Climatopolis: How Our Cities Will Thrive in the Hotter Future” by Matthew E. Kahn. The EconLit Abstract of the reviewed work begins “Explores how cities will adapt to the challenges of climate change, focusing on how geographical and socioeconomic factors will affect the quality of urban life in a hotter world. Discusses too much gas; what we've done when our cities have blown up; king of the hill; the case of Los Angeles; whether Manhattan will flood; whether China's cities will go green; effects and adaptations in developing countries; seize the day--opportunities from our hotter future; and the future of cities. Kahn is Professor with the Institute of the Environment, the Department of Economics, and the Department of Public Policy at the University of California, Los Angeles. Index.”

Construction of Alkylated Stereogenic Centers: The Zhu Synthesis of (−)-Rhazinilam

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Chemistry ◽  
University Of California ◽  
Shanghai Institute ◽  
Stereogenic Centers ◽  
Cu Catalyst ◽  
The University

Zheng Huang of the Shanghai Institute of Organic Chemistry (J. Am. Chem. Soc. 2014, 136, 15501) and Zhan Lu of Zhejiang University (Org. Lett. 2014, 16, 6452) effected enantioselective hydroboration of α-alkyl styrenes, as illustrated by the conversion of 1 to 2. Stephen L. Buchwald of MIT devised (J. Am. Chem. Soc. 2014, 136, 15913) a Cu catalyst for the anti-Markovnikov hydroamination of 3 with 4 to give 5. John F. Hartwig of the University of California, Berkeley developed (Angew. Chem. Int. Ed. 2014, 53, 8691, 12172) an Ir catalyst for the enantioselective coupling of 6 with 7 to give 8.

Reactions of Alkenes

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Iron Catalyst ◽  
Catalytic Reduction ◽  
Indian Institute ◽  
Yale University ◽  
Terminal Alkene ◽  
National University ◽  
Institute Of Technology ◽  
La Jolla ◽  
The University

The catalytic reduction of the alkene 1 gave the cis-fused product (not illustrated), by kinetic H₂ addition to the less congested face of the alkene. Ryan A. Shenvi of Scripps La Jolla found (J. Am. Chem. Soc. 2014, 136, 1300) conditions for stepwise HAT, con­verting 1 to the thermodynamically-favored trans-fused ketone 2. Seth B. Herzon of Yale University devised (J. Am. Chem. Soc. 2014, 136, 6884) a protocol for the reduc­tion, mediated by 4, of the double bond of a haloalkene 3 to give the saturated halide 5. The Shenvi conditions also reduced a haloalkene to the saturated halide. Daniel J. Weix of the University of Rochester and Patrick L. Holland, also of Yale University, established (J. Am. Chem. Soc. 2014, 136, 945) conditions for the kinetic isomerization of a terminal alkene 6 to the Z internal alkene 7. Christoforos G. Kokotos of the University of Athens showed (J. Org. Chem. 2014, 79, 4270) that the ketone 9, used catalytically, markedly accelerated the Payne epoxidation of 8 to 10. Note that Helena M. C. Ferraz of the Universidade of São Paulo reported (Tetrahedron Lett. 2000, 41, 5021) several years ago that alkene epoxidation was also easily carried out with DMDO generated in situ from acetone and oxone. Theodore A. Betley of Harvard University prepared (Chem. Sci. 2014, 5, 1526) the allylic amine 12 by reacting the alkene 11 with 1-azidoadamantane in the presence of an iron catalyst. Rodney A. Fernandes of the Indian Institute of Technology Bombay developed (J. Org. Chem. 2014, 79, 5787) efficient conditions for the Wacker oxida­tion of a terminal alkene 6 to the methyl ketone 13. Yong-Qiang Wang of Northwest University oxidized (Org. Lett. 2014, 16, 1610) the alkene 6 to the enone 14. Peili Teo of the National University of Singapore devised (Chem. Commun. 2014, 50, 2608) conditions for the Markovnikov hydration of the alkene 6 to the alcohol 15. Internal alkenes were inert under these conditions, but Yoshikazo Kitano of the Tokyo University of Agriculture and Technology effected (Synthesis 2014, 46, 1455) the Markovnikov amination (not illustrated) of more highly substituted alkenes.

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