Catalytic Enantioselective Pinacol and Meinwald Rearrangements for the Construction of Quaternary Stereocenters
作者:Hua Wu、Qian Wang、Jieping Zhu
DOI:10.1021/jacs.9b04551
日期:2019.7.24
enantioselective pinacolrearrangement is ex-tremely challenging due to the likelihood involvement of the carbeni-um intermediate that renders the stereochemical communication between catalyst and substrate difficult to achieve. Herein, we report chiral N-triflyl phosphoramide-catalyzed enantioselective pinacolrearrangement of 1,2-tertiary diols and mechanistically related Meinwald rearrangement of tetrasubstituted
The present invention relates to compounds of formula (I) in the form of any one of its stereoisomers or a mixture thereof, and wherein R
1
represents a substituent of the benzene ring and is a bromine atom or a linear, branched or cyclic C
1-8
alkyl, alkenyl, alkoxy or alkenyloxy group; R
2
represents a C
1-3
alkyl group; and R
3
represents a hydrogen atom or a methyl or ethyl group; and their use as perfuming ingredients, for instance to impart odor notes of the watery/ozone type.
The present invention relates to compounds of formula (I) in the form of any one of its stereoisomers or a mixture thereof, and wherein R1 represents a substituent of the benzene ring and is a bromine atom or a linear, branched or cyclic C1-8 alkyl, alkenyl, alkoxy or alkenyloxy group; R2 represents a C1-3 alkyl group; and R3 represents a hydrogen atom or a methyl or ethyl group; and their use as perfuming ingredients, for instance to impart odor notes of the watery/ozone type.
Synthesis of Ketones through Microwave Irradiation Promoted Metal-Free Alkylation of Aldehydes by Activation of C(sp<sup>3</sup>)–H Bond
作者:Xinying Zhang、Zhangxin Wang、Xuesen Fan、Jianji Wang
DOI:10.1021/acs.joc.5b01824
日期:2015.11.6
In this paper, a novel methodology for the synthesis of ketones via microwave irradiation promoted direct alkylation of aldehydes by activation of the inert C(sp(3))-H bond has been developed. Notably, the reactions were accomplished under metal-free conditions and used commercially available aldehydes and cycloalkanes as substrates without prefunctionalization. By using this novel method, an alternative synthetic approach toward the key intermediates for the preparation of the pharmaceutically valuable oxaspiroketone derivatives was successfully established.
Central Nervous System Depressants. V. Polyhydroxy and Methoxyphenyl Ketones, Carbinols, and Derivatives
作者:Robert Bruce Moffett、A. R. Hanze、Patrick H. Seay