Synthesis of Fused Bicyclic Aminals through Sequential Gold/Lewis Acid Catalysis
摘要:
A novel sequential catalysis by combining gold catalysis with early transition metal catalysis was developed. Biologically important bicyclo[4.n.0] aminals were obtained under very mild conditions.
Protonation of Homoenolate Equivalents Generated by N-Heterocyclic Carbenes
作者:Karl Scheidt、Brooks Maki、Audrey Chan
DOI:10.1055/s-2008-1072516
日期:2008.4
Homoenolate equivalents are generated by Lewis basic N-heterocyclic carbene catalysts and then protonated to generate efficiently saturated esters from unsaturated aldehydes. This reactivity is extended to the generation of beta-acylvinyl anions from alkynyl aldehydes. The asymmetric protonation of a homoenolate equivalent generated from a beta,beta-disubstituted aldehyde can be accomplished with a
1,4-Bis-Dipp/Mes-1,2,4-Triazolylidenes: Carbene Catalysts That Efficiently Overcome Steric Hindrance in the Redox Esterification of α- and β-Substituted α,β-Enals
作者:Veera Reddy Yatham、Wacharee Harnying、Darius Kootz、Jörg-M. Neudörfl、Nils E. Schlörer、Albrecht Berkessel
DOI:10.1021/jacs.5b11796
日期:2016.3.2
2,4-triazolium salts were synthesized and evaluated as (pre)catalysts in the redox esterification of various α- or β-substituted enals. In particular the 1,4-bis-Mes/Dipp-1,2,4-triazolylidenes overcome the above limitations and efficiently catalyze the redox esterification of a whole series of α/β-substituted enals hitherto not amenable to NHC-catalyzed transformations. The synthetic value of 1,4-bis-Mes/Dipp-1
An oil-in-water emulsion cosmetic composition is provided. The oil-in-water emulsion cosmetic composition comprises a carboxylic acid modified silicone (A) that has a specific chemical structure and is liquid at room temperature, an oil agent (B), and water (C). The oil-in-water emulsion cosmetic composition can provide a cosmetic film with high stability and excellent water resistance.
Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: oxidative NHC catalysis via multistep electron transfer
作者:L. Ta、A. Axelsson、H. Sundén
DOI:10.1039/c5gc01965f
日期:——
Employing a system of electrontransfer mediators (ETMs) enables the use of oxygen as the terminal oxidant for oxidative NHC-catalyzed reactions.
使用电子传递介体(ETM)系统可以将氧气用作NHC催化氧化反应的末端氧化剂。
COSMETIC
申请人:Dow Toray Co., Ltd.
公开号:US20210244641A1
公开(公告)日:2021-08-12
A cosmetic composition is provided. The cosmetic composition comprises a carboxylic acid modified silicone (A) that has a specific chemical structure and is liquid at room temperature. The cosmetic composition also comprises an oil agent (B). The cosmetic composition generally provides a cosmetic film having excellent water resistance, and can be easily removed by normal soap and water.