Josiphos-Catalyzed Asymmetric Homodimerization of Ketoketenes
作者:Ahmad A. Ibrahim、Pei-Hsun Wei、Gero D. Harzmann、Nessan J. Kerrigan
DOI:10.1021/jo101867m
日期:2010.11.19
phosphine-catalyzed homodimerization of ketoketenes that provides access to a variety of highlysubstitutedketoketenedimerβ-lactones (11 examples) is reported. The Josiphos catalytic system displays good to excellent enantioselectivity (up to 96% ee). Ring-opening reactions of the enantioenriched ketoketenedimers were also carried out to access 1,3-diketones, enolesters, and β-hydroxyketones with good
CATALYST AND METHOD FOR HYDROGENATION OF 1,3-CYCLOBUTANEDIKETONE COMPOUND
申请人:INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
公开号:US20170334815A1
公开(公告)日:2017-11-23
Catalyst for hydrogenation of 1,3-cyclobutanediketone compound is provided, which includes a support and VIIIB group transition metal loaded thereon. The support includes a first oxide powder with a surface wrapped by a second oxide. The first oxide includes silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, zinc oxide, or a combination thereof. The second oxide has a composition of M
x
Al
(1-x)
O
(3-x)/2
, M is alkaline earth metal, and x is from 0.3 to 0.7.
Phosphine-catalyzed stereoselective dimerizations of ketenes
作者:Ahmad A. Ibrahim、Pei-Hsun Wei、Gero D. Harzmann、Divya Nalla、Mukulesh Mondal、Kraig A. Wheeler、Nessan J. Kerrigan
DOI:10.1016/j.tet.2020.131838
日期:2021.1
Full details of optimisation studies of the phosphine-catalyzed ketene homodimerization reaction and the detailed development of an asymmetric variant are discussed. Studies towards the development of a phosphine-catalyzed ketene heterodimerization reaction are revealed. A discussion of possible reaction mechanisms for the dimerization reactions, supported by spectroscopic analysis of intermediates