Unanticipated Silyl Transfer in Enantioselective α,β-Unsaturated Acyl Ammonium Catalysis Using Silyl Nitronates
作者:Anastassia Matviitsuk、Mark D. Greenhalgh、James E. Taylor、Xuan B. Nguyen、David B. Cordes、Alexandra M. Z. Slawin、David W. Lupton、Andrew D. Smith
DOI:10.1021/acs.orglett.9b04404
日期:2020.1.3
The use of silyl nitronates is reported for the isothiourea-catalyzed synthesis of γ-nitro-substituted silyl esters containing up to two contiguous stereocenters in good yields with excellent enantioselectivities (up to 93% yield and 99:1 er). The serendipitously discovered formation of silyl ester products in this reaction demonstrates a novel platform for catalyst turnover in α,β-unsaturated acyl
Synthesis of Isoxazolines from Nitroalkanes
<i>via</i>
a [4+1]‐Annulation Strategy
作者:Pavel Yu. Ushakov、Elizaveta A. Khatuntseva、Yulia V. Nelyubina、Andrey A. Tabolin、Sema L. Ioffe、Alexey Yu. Sukhorukov
DOI:10.1002/adsc.201901000
日期:2019.12.3
using the [4+1]‐annulation of α‐keto‐stabilized sulfur ylides with N,N‐bis(siloxy)enamines derived from aliphatic nitro compounds. The resulting 5‐keto‐substituted isoxazolines were shown to be convenient precursors of polysubstituted 3‐hydroxypyrrolidines via the one‐pot catalytic N−O hydrogenolysis/intramolecular reductive amination sequence. Application of this approach to the formal synthesis of Merck's
Tandem double acylation/[3,3]-rearrangement of aliphatic nitro compounds: a route to α-oxygenated oxime derivatives
作者:Yulia A. Antonova、Yulia V. Nelyubina、Alexey Yu. Sukhorukov、Sema L. Ioffe、Andrey A. Tabolin
DOI:10.1039/c9ob01005j
日期:——
A new tandem double acylation/rearrangement reaction of nitro compounds is described. It has a broad substrate scope allowing the mild and efficient synthesis of α-acyloxy oxime esters in high yields and regioselectivity. According to the obtained data, the mechanism for transformation was proposed. The utility of the obtained α-hydroxy oxime esters was demonstrated.