Sequenced elimination–reduction and elimination–cyclopropanation reactions of 2,3-epoxyamides promoted by samarium diiodide. Synthesis of 2,3-dideuterioamides and cyclopropanamides
摘要:
An easy and general sequenced elimination/reduction or elimination/cyclopropanation process promoted by samarium diiodide or/and CH2I2/Sm provide an efficient method for synthesising 2,3-dideuterioamides 3 or cyclopropanamides 8, respectively. The transformations take place in high yields and with total or high selectivity from the easily available 2,3-epoxyamides. (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis of (E)-α-Hydroxy-β,γ-Unsaturated Amides with High Selectivity fromα,β-Epoxyamides by Using Catalytic Samarium Diiodide or Triiodide
作者:José M. Concellón、Pablo L. Bernad、Eva Bardales
DOI:10.1002/chem.200305375
日期:2004.5.17
stereoselective synthesis of (E)-alpha-hydroxy-beta,gamma-unsaturated amides starting from alpha,beta-epoxyamides, by using catalytic SmI2 or SmI3, was achieved. This transformation can also be carried out by using SmI2 generated in situ from samarium powder and diiodomethane. The starting compounds1 are easily prepared by the reaction of enolates derived from alpha-chloroamides with ketones at -78 degrees
Unusual reductive cleavage of 3-aryl-2,3-epoxyamides by using samarium diiodide. Synthesis of 3-aryl-3-deuterio-2-hydroxyamides with total regioselectivity
作者:José M. Concellón、Eva Bardales、Cecilia Gómez
DOI:10.1016/s0040-4039(03)01201-2
日期:2003.7.7
Ring-opening of 3-aryl-2,3-epoxyamides 1 was achieved by using samarium diiodide and D2O, yielding 3-aryl-3-deuterio-2-hydroxyamides 2 with total regioselectivity. The starting compounds 1 were easily prepared by reaction of the corresponding lithium or potassium enolates of α-chloroamides with aldehydes or ketones. When the reaction was carried out in the presence of H2O instead of D2O, the corresponding