ChemInform Abstract: Organocatalytic Enantioselective Conjugate Addition of Malonic Acid Half Thioesters to Coumarin-3-carboxylic Acids Using N-Heteroarenesulfonyl Cinchona Alkaloid Amides.

ChemInform ◽  
2016 ◽  
Vol 47 (32) ◽  
Author(s):  
Shuichi Nakamura ◽  
Ayaka Toda ◽  
Masahide Sano ◽  
Tsubasa Hatanaka ◽  
Yasuhiro Funahashi
Keyword(s):  
Carboxylic Acids ◽  
Malonic Acid ◽  
Conjugate Addition ◽  
Cinchona Alkaloid

Organocatalytic Enantioselective Conjugate Addition of Malonic Acid Half Thioesters to Coumarin-3-carboxylic Acids UsingN-HeteroarenesulfonylCinchonaAlkaloid Amides

2016 ◽  
Vol 358 (7) ◽  
pp. 1029-1034 ◽  
Author(s):  
Shuichi Nakamura ◽  
Ayaka Toda ◽  
Masahide Sano ◽  
Tsubasa Hatanaka ◽  
Yasuhiro Funahashi
Keyword(s):  
Carboxylic Acids ◽  
Malonic Acid ◽  
Conjugate Addition

Conjugate Addition of RMgX–3MeLi to α,β-Unsaturated Amides and α,β-Unsaturated Carboxylic Acids

2007 ◽  
Vol 36 (6) ◽  
pp. 736-737 ◽  
Author(s):  
Mikiko Kikuchi ◽  
Satomi Niikura ◽  
Nao Chiba ◽  
Nahoko Terauchi ◽  
Morio Asaoka
Keyword(s):  
Carboxylic Acids ◽  
Conjugate Addition ◽  
Unsaturated Carboxylic Acids

scholarly journals Copper-Promoted Conjugate Addition of Carboxylic Acids to Ethenesulfonyl Fluoride (ESF) for Constructing Aliphatic Sulfonyl Fluorides

ACS Omega ◽  
2021 ◽  
Author(s):  
Xu Zhang ◽  
Yu-Mei Huang ◽  
Hua-Li Qin ◽  
Zhang Baoguo ◽  
K. P. Rakesh ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Conjugate Addition

Conjugate Addition of RMgX—3MeLi to α,β-Unsaturated Amides and α,β-Unsaturated Carboxylic Acids.

ChemInform ◽  
2007 ◽  
Vol 38 (45) ◽  
Author(s):  
Mikiko Kikuchi ◽  
Satomi Niikura ◽  
Nao Chiba ◽  
Nahoko Terauchi ◽  
Morio Asaoka
Keyword(s):  
Carboxylic Acids ◽  
Conjugate Addition ◽  
Unsaturated Carboxylic Acids

Cationic Pd(II)/bipyridine-catalyzed conjugate addition of arylboronic acids to α,β-unsaturated carboxylic acids in aqueous media

2018 ◽  
Vol 59 (13) ◽  
pp. 1192-1195 ◽  
Author(s):  
Yuxin Ni ◽  
Kaixuan Song ◽  
Kai Shen ◽  
Zhenyu Yang ◽  
Rui Liu ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Aqueous Media ◽  
Conjugate Addition ◽  
Arylboronic Acids ◽  
Unsaturated Carboxylic Acids

Alkaloid Synthesis: Mearsine (Taylor), Cephalotaxine (Li), Cocaine (Shing), Quinine (Hatakeyama), Cleavamine (Bennasar), Strychnine(Vanderwal)

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Hong Kong ◽  
Malonic Acid ◽  
Selective Hydrogenation ◽  
Aqueous Ammonia ◽  
Conjugate Addition ◽  
University Of California ◽  
The Past ◽  
Chinese University ◽  
Alkaloid Synthesis ◽  
The University

Richard J. K. Taylor of the University of York employed (Tetrahedron Lett. 2011, 52, 2024) the Jørgensen protocol to add 2 to 1, to give the enantiomerically enriched cyclohexenone 3. Condensation of 3 with aqueous ammonia led directly to (-)-mearsine 4. Wei-Dong Z. Li of Nankai University found (Org. Lett. 2011, 13, 3538) that the intermediate from Dibal reduction of the lactone 5 underwent Nazarov cyclization, giving the α-hydroxy cyclopentenone 6. After acetylation, deprotection gave an amine that cyclized with high diastereocontrol, leading to (±)-cephalotaxine 7. Tony K. M. Shing of the Chinese University of Hong Kong cyclized (Org. Lett. 2011, 13, 2916) the aldehyde 8 by exposure to 9. The product 10 was carried on to (-)-cocaine 11, as well as several hydroxylated cocaine derivatives. Susumi Hatakeyama of Nagasaki University found (Tetrahedron Lett. 2011, 52, 923) that exposure of the simple prochiral aldehyde 12 to catalytic proline transformed it, after reduction, into the cyclized diol 13 in high ee. The diol 13 was readily carried on to quinine 14. M.-Lluïsa Bennasar of the University of Barcelona devised (Org. Lett. 2011, 13, 2042) Pd-catalyzed conditions for the cyclization of 15 that selectively delivered the unstable kinetic product 18. Selective hydrogenation of the more reactive bridgehead alkene then led to cleavamine 17. The alkene 16 is also prochiral, so it is possible that a catalyst could be found that would deliver 17 in high ee. The synthesis of the heptacyclic alkaloid strychnine 23 would, in the past, have been a major undertaking. Christopher D. Vanderwal of the University of California, Irvine, prepared (Chem. Sci. 2011, 2, 649) 23 in just six linear steps. The dienyl aldehyde 18 was available in two steps from tryptophyl bromide. Exposure to t -BuOK cyclized 18 to 19. N-deallylation followed by alkylation with 20 provided 21, setting the stage for a truly spectacular Brook rearrangement/conjugate addition, to give the Wieland-Gumlich aldehyde 22. The known condensation with malonic acid completed the preparation of 23.

Enantioselective Preparation of Alcohols and Amines:The Suh Synthesis of (-)-Macrosphelide J

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Conjugate Addition ◽  
Aliphatic Aldehyde ◽  
Geometric Control ◽  
Cinchona Alkaloid ◽  
University Of Virginia ◽  
Aliphatic Aldehydes ◽  
Salen Complex ◽  
Complementary Approach ◽  
National University ◽  
The University

Keiji Maruoka of Kyoto University (J. Am. Chem. Soc. 2009, 131, 3450) and Yujiro Hayashi of the Tokyo University of Science (Chem. Commun. 2009, 3083) independently developed organocatalysts for the enantioselective α-benzoylation of aliphatic aldehydes such as 1. The product 3 can be readily carried on to, inter alia, either enantiomer of the epoxide. Chengjian Zhu of Nanjing University designed (Adv. Synth. Cat. 2009, 351, 920) a chiral salen complex that mediated the enantioselective opening of both cyclohexene oxide (4) and cyclopentene oxide. This reagent combination might also engage just one of the two enantiomers of a racemic cycloalkene epoxide. Lin Pu of the University of Virginia established (Organic Lett. 2009, 11, 2441) a BINOL catalyst for the addition of ethyl propiolate 7 to an aliphatic aldehyde 6 to give the alcohol 8 in high ee. In a complementary approach, Do Hyun Ryu of Sungkyunkwan University found (Angew. Chem. Int. Ed. 2009, 48, 4398) that an oxazaborolidinium salt catalyzed the addition of 7 to 9 to give 10 with high ee and high geometric control. Jianliang Xiao of the University of Liverpool devised (J. Am. Chem. Soc. 2009, 131, 6967) an Ir catalyst for the enantioselective reductive amination of a ketone 11 to the amine 13 . Karl B. Hansen, Yi Hsiao. and Feng Xu, then all at Merck/Rahway, showed (J. Am. Chem. Soc. 2009, 131, 8798) that it was possible to hydrogenate a vinylogous primary amide 14 to the amine 15 with high enantiocontrol. Takashi Ooi of Nagoya University designed (J. Am. Chem. Soc. 2009, 131, 7242) a chiral P-spiro tetraaminophosphonium catalyst that mediated the enantioselective addition of anilines to nitroalkenes such as 16. The product 18 could be carried on to the 1,2-diamine, or to the α-amino acid. Masahiro Terada of Tohoku University devised (Angew. Chem. Int. Ed. 2009, 48, 2553) a BINOL-derived phosphonic acid to catalyze the enantioselective 1,2-addition of the enamide 20 to the imine derived from 19. Yixin Lu of the National University of Singapore found (Organic Lett. 2009, 11, 1721) that a cinchona alkaloid-derived thiourea effectively catalyzed the enantioselective conjugate addition of nitroalkanes such as 22 to the acceptor 23.

scholarly journals Direct Enantioselective Conjugate Addition of Carboxylic Acids with Chiral Lithium Amides as Traceless Auxiliaries

2015 ◽  
Vol 137 (2) ◽  
pp. 656-659 ◽  
Author(s):  
Ping Lu ◽  
Jeffrey J. Jackson ◽  
John A. Eickhoff ◽  
Armen Zakarian
Keyword(s):  
Carboxylic Acids ◽  
Conjugate Addition ◽  
Lithium Amides
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