Oxidative and Enantioselective Cross-Coupling of Aldehydes and Nitromethane Catalyzed by Diphenylprolinol Silyl Ether
作者:Yujiro Hayashi、Takahiko Itoh、Hayato Ishikawa
DOI:10.1002/anie.201006885
日期:2011.4.18
Synthetically important β‐substituted γ‐nitro aldehydes have been synthesized with excellent enantioselectivity by the cross‐coupling reaction of β‐aryl substituted aldehydes or γ,δ‐unsaturated aldehydes and nitromethane using 2,3‐dichloro‐5,6‐dicyanoquinone (DDQ) and diphenylprolinol silyl ether as an oxidant and catalyst, respectively (see scheme; TMS=trimethylsilyl).
Diphenylprolinol Silyl Ether as Catalyst of an Asymmetric, Catalytic, and Direct Michael Reaction of Nitroalkanes with α,β-Unsaturated Aldehydes
作者:Hiroaki Gotoh、Hayato Ishikawa、Yujiro Hayashi
DOI:10.1021/ol702545z
日期:2007.12.1
A catalyticenantioselective direct conjugate addition of nitroalkanes to alpha,beta-unsaturated aldehydes using diphenylprolinolsilylether as an organocatalyst has been developed. Using this methodology as a key step, short syntheses of therapeutically useful compounds have also been accomplished.
Asymmetric Michael Reaction of Acetaldehyde with Nitroolefins Catalyzed by Highly Water-Compatible Organocatalysts in Aqueous Media
作者:Yupu Qiao、Junpeng He、Bukuo Ni、Allan D. Headley
DOI:10.1002/adsc.201200215
日期:2012.10.8
A novel category of diarylprolinol silylether catalysts which contain different lengths of alkylamine tags, was designed and synthesized. These catalysts were used, along with benzoic acid as the co-catalyst, to catalyze the asymmetric Michael reaction of the highly reactive acetaldehyde with nitroolefins. For the reactions studied, this catalyticsystem exhibited high reactivity in brine without
Reactivity and Selectivity of Iminium Organocatalysis Improved by a Protein Host
作者:Alexander R. Nödling、Katarzyna Świderek、Raquel Castillo、Jonathan W. Hall、Antonio Angelastro、Louis C. Morrill、Yi Jin、Yu-Hsuan Tsai、Vicent Moliner、Louis Y. P. Luk
DOI:10.1002/anie.201806850
日期:2018.9.17
There has been growing interest in performing organocatalysis within a supramolecular system as a means of controlling reaction reactivity and stereoselectivity. Here, a protein is used as a host for iminium catalysis. A pyrrolidine moiety is covalently linked to biotin and introduced to the proteinhost streptavidin for organocatalytic activity. Whereas in traditional systems stereoselectivity is
Paraldehyde as an Acetaldehyde Precursor in Asymmetric Michael Reactions Promoted by Site-Isolated Incompatible Catalysts
作者:Xinyuan Fan、Carles Rodríguez-Escrich、Sonia Sayalero、Miquel A. Pericàs
DOI:10.1002/chem.201302087
日期:2013.8.12
song of ice and fire! The usually innocent paraldehyde can be used as an acetaldehydeprecursor in an organocatalytic asymmetricMichael addition (see scheme) thanks to the proper combination of two immobilized catalysts. The site isolation induced by the polymeric supports has proven crucial to preclude deactivation of the otherwise incompatiblecatalysts.