Highly Practical Copper(I)/TEMPO Catalyst System for Chemoselective Aerobic Oxidation of Primary Alcohols
作者:Jessica M. Hoover、Shannon S. Stahl
DOI:10.1021/ja206230h
日期:2011.10.26
Aerobicoxidation reactions have been the focus of considerable attention, but their use in mainstream organic chemistry has been constrained by limitations in their synthetic scope and by practical factors, such as the use of pure O(2) as the oxidant or complex catalyst synthesis. Here, we report a new (bpy)Cu(I)/TEMPO catalyst system that enables efficient and selective aerobicoxidation of a broad
Rhodium catalysed carbonylation of homoallylic alcohols to spiropyrans bearing quaternary centres
作者:Beate Kitsos-Rzychon、Peter Eilbracht
DOI:10.1016/s0040-4020(98)00637-1
日期:1998.9
A convenient preparation of substituted spiropyrans via rhodiumcatalysed hydroformylation of homoallylic alcohols, followed by a condensation sequence to form hemiacetals and 2,2,3,3-tetraalkyl-4[H]-pyrans, is described.
Aerobic oxidation of 1,n- and 1,omega-diols with (ON)Ru(salon) 1 as the catalyst was found to give the corresponding lactols in almost quantitative yields. Furthermore, in the oxidation of 2,2-dimethylalkane-1,omega-diols, less sterically hindered omega-alcohols were found to be preferentially oxidized when (ON)Ru(salen) 6 was used as the catalyst. n-Decanol was preferentially oxidized in the presence of 2,2-dimethylpropanol also by using 6 as the catalyst. (C) 2002 Elsevier Science Ltd. All rights reserved.
Catalytic Asymmetric Synthesis of Cyclohexanes by Hydrogen Borrowing Annulations
作者:Roly J. Armstrong、Wasim M. Akhtar、Tom A. Young、Fernanda Duarte、Timothy J. Donohoe
DOI:10.1002/anie.201907514
日期:2019.9.2
Hydrogen borrowing catalysis serves as a powerful alternative to enolate alkylation, enabling the direct coupling of ketones with unactivated alcohols. However, to date, methods that enable control over the absolute stereochemical outcome of such a process have remained elusive. Here we report a catalytic asymmetric method for the synthesis of enantioenriched cyclohexanes from 1,5‐diols via hydrogen
A new twist: The catalytic asymmetric semipinacol rearrangement reaction of 2‐oxo allylic alcohols 1 in the presence of a catalytic amount of chiral phosphoric acid (R)‐2 a or its silver salt (R)‐2 b affords enantiomerically pure spiroethers 3.