Isothiourea-catalysed enantioselective radical conjugate addition under batch and flow conditions
作者:Roberto del Río-Rodríguez、Matthew T. Westwood、Marina Sicignano、Martin Juhl、Jose A. Fernández-Salas、José Alemán、Andrew D. Smith
DOI:10.1039/d2cc02432b
日期:——
The photocatalytic generation of α-amino radicals is combined with chiral isothiourea derived α,β-unsaturatedacyl ammonium intermediates. The reaction proceeds VIA a [3+2] radical-polar crossover mechanism to generate γ-lactams in good yields and enantioselectivities. The enantioselective radical conjugate addition was carried out under batch and flow conditions.
Stereoselective α-Fluorination of <i>N</i>-Acyloxazolidinones at Room Temperature within 1 h
作者:Joseph Alvarado、Aaron T. Herrmann、Armen Zakarian
DOI:10.1021/jo500957d
日期:2014.7.3
A direct alpha-fluorination of N-acyloxazolidinones based on the unique reactivity of group IVa metal enolates has been developed. The reaction is an experimentally simple, low-cost, quick, and energy-efficient alternative for asymmetric alpha-fluorination of N-acyloicazolidinones. Preliminary studies have shown compatibility with alkyl, alkenyl, and alkynyl, aromatic, and several heteroaromatic substituents. High diastereoselectivities have been achieved with most substrates tested, and the reaction is typically complete within 1 h at ambient temperature.
The preparation of simplified scyphostatin analogues using a tethered aminohydroxylation (TA) strategy
作者:Martin N. Kenworthy、Graeme D. McAllister、Richard J.K. Taylor
DOI:10.1016/j.tetlet.2004.07.012
日期:2004.8
The first tethered aminohydroxylation reaction employing a tertiary alcohol is reported as part of a route to prepare analogues of the naturally occurring sphingomyelinase inhibitor, scyphostatin. The tethered aminohydroxylation of 1-allylcyclohexanol produces the beta-amino alcohol product, in protected form, with the required regiochemistry. Two approaches to the installation of the lipophilic side chain are described and the successful route used to prepare five novel scyphostatin analogues, one containing the natural lower side chain. (C) 2004 Elsevier Ltd. All rights reserved.