2031-46-1Relevant articles and documents
Chiral conflict. The effect of temperature on the helical sense of a polymer controlled by the competition between structurally different enantiomers: From dilute solution to the lyotropic liquid crystal state
Tang, Kai,Green, Mark M.,Cheon, Kap Soo,Selinger, Jonathan V.,Garetz, Bruce A.
, p. 7313 - 7323 (2003)
Helical polymers appended with paired structurally different enantiomers, which have opposing helical sense preferences, yield a new kind of relationship between optical activity and temperature, and also reveal unusual details of the nature of chiral int
Asymmetric Umpolung Hydrogenation and Deuteration of Alkenes Catalyzed by Nickel
Guo, Siyu,Wang, Xiuhua,Zhou, Jianrong Steve
supporting information, p. 1204 - 1207 (2020/02/04)
Nickel-catalyzed asymmetric hydrogenation of several types of alkenes proceeds in high enantioselectivity, using acetic acid or water as the hydrogen source and indium powder as electron donor. The scope of alkenes herein include α,β-unsaturated esters, n
Enantioselective β-Protonation of Enals via a Shuttling Strategy
Chen, Jiean,Yuan, Pengfei,Wang, Leming,Huang, Yong
, p. 7045 - 7051 (2017/06/01)
Remote asymmetric protonation is a longstanding challenge due to the small size of protons. Reactions involving electron-deficient olefins pose a further difficulty due to the electrophilic nature of these substrates. We report a shuttling system that delivers a proton in a highly enantioselective manner to the β-carbon of enals using a chiral N-heterocyclic carbene (NHC) catalyst. Choices of a Br?nsted base shuttle and a Br?nsted acid cocatalyst are critical for highly stereoselective β-protonation of the homoenolate intermediate and regeneration of the NHC catalyst results in functionalization of the carbonyl group. Thioesters with a β-chiral center were prepared in a redox-neutral transformation with an excellent yield and ee.