ChemInform Abstract: Highly Enantioselective Conjugate Addition of Nitroalkanes to Enones Catalyzed by Cinchona Alkaloid Derived Primary Amine.

ChemInform ◽  
2013 ◽  
Vol 44 (42) ◽  
pp. no-no
Author(s):  
Wenjing Liu ◽  
Desheng Mei ◽  
Wei Wang ◽  
Wenhu Duan
Keyword(s):  
Primary Amine ◽  
Conjugate Addition ◽  
Cinchona Alkaloid

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.

The role of reversibility in the enantioselective conjugate addition of α,α-disubstituted aldehydes to nitro-olefins catalyzed by primary amine thioureas

2014 ◽  
Vol 4 (10) ◽  
pp. 3505-3509 ◽  
Author(s):  
Yining Ji ◽  
Donna G. Blackmond
Keyword(s):  
Primary Amine ◽  
Conjugate Addition ◽  
Mechanistic Insight

Identification of intermediates in the asymmetric conjugate addition of aldehdyes to nitro-olefins catalyzed by primary amine thioureas add mechanistic insight.

scholarly journals Organocatalytic Asymmetric Conjugate Addition of Aldehydes to Maleimides and Nitroalkenes in Deep Eutectic Solvents

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4058 ◽  
Author(s):  
Alejandro Torregrosa-Chinillach ◽  
Alba Sánchez-Laó ◽  
Elisa Santagostino ◽  
Rafael Chinchilla
Keyword(s):  
Primary Amine ◽  
Room Temperature ◽  
Deep Eutectic Solvents ◽  
Conjugate Addition ◽  
Reaction Media

A chiral primary amine-salicylamide is used as an organocatalyst for the enantioselective conjugate addition of α,α-disubstituted aldehydes to maleimides and nitroalkenes. The reactions are performed in deep eutectic solvents as reaction media at room temperature, leading to the corresponding adducts with enantioselectivities up to 88% (for maleimides) and 80% (for nitroalkenes). Catalyst and solvent can be recovered and reused.

Cinchona alkaloid-based chiral catalysts act as highly efficient multifunctional organocatalysts for the asymmetric conjugate addition of malonates to nitroolefins

2015 ◽  
Vol 13 (40) ◽  
pp. 10216-10225 ◽  
Author(s):  
Veeramanoharan Ashokkumar ◽  
Ayyanar Siva
Keyword(s):  
Michael Addition ◽  
Quaternary Ammonium ◽  
Conjugate Addition ◽  
Quaternary Ammonium Salts ◽  
Cinchona Alkaloid ◽  
Ammonium Salts ◽  
Addition Reactions ◽  
Chiral Catalysts ◽  
Reaction Conditions ◽  
Highly Efficient

New pentaerythritol tetrabromide based chiral quaternary ammonium salts have been prepared and used as organocatalysts for enantioselective Michael addition reactions between various nitroolefins and Michael donors under mild reaction conditions with very good chemical yields and ee's.

Sign in / Sign up

Export Citation Format

Share Document