Microwave-assisted synthesis of α-ethoxycarbamates
摘要:
An efficient and reproducible synthesis of various alpha-ethoxycarbamates is described via a microwave heating mode. Compared to the thermal process. the microwave dielectric heating induces a dramatic reduction of the reaction time and the improvement of the yields. The reaction is general since applicable to aromatic and aliphatic aldehydes with various primary amines. Several examples involving chiral aldehydes have also been considered. (C) 2009 Elsevier Ltd. All rights reserved.
Microwave-assisted synthesis of α-ethoxycarbamates
作者:Alexandre Lumbroso、Floris Chevallier、Isabelle Beaudet、Jean-Paul Quintard、Thierry Besson、Erwan Le Grognec
DOI:10.1016/j.tet.2009.09.023
日期:2009.11
An efficient and reproducible synthesis of various alpha-ethoxycarbamates is described via a microwave heating mode. Compared to the thermal process. the microwave dielectric heating induces a dramatic reduction of the reaction time and the improvement of the yields. The reaction is general since applicable to aromatic and aliphatic aldehydes with various primary amines. Several examples involving chiral aldehydes have also been considered. (C) 2009 Elsevier Ltd. All rights reserved.
syn-Allylstannation of N-Acyliminium Intermediates by Tributyl[γ-(silyloxy)allyl]stannanes: A Key Reaction for the Diastereoselective Synthesis of Polyhydroxypiperidines and Polyhydroxyazepanes
作者:Floris Chevallier、Alexandre Lumbroso、Isabelle Beaudet、Erwan Le Grognec、Loïc Toupet、Jean-Paul Quintard
DOI:10.1002/ejoc.201100302
日期:2011.8
The allylstannation of N-alkenyl N-acyliminium intermediates by tributyl[gamma-(silyloxy)allyl]stannanes afforded the expected adducts with a high syn-selectivity (up to 99: 1). Ensuing ring-closing metathesis afforded dehydropiperidines or dehydroazepanes which were engaged in a stereoselective dihydroxylation reaction leading to polyhydroxypiperidines or polyhydroxyazepanes in good yields. This sequence