A Novel One-Pot Stereoselective Synthesis of <i>N</i>-[(<i>E</i>)-Homocinnamyl] Amides
作者:Xian Huang、Wanli Chen、Hongwei Zhou
DOI:10.1055/s-2004-822369
日期:——
N-[(E)-Homocinnamyl] amides were stereoselectively synthesized by the reaction of the methylenecyclopropanes (MCPs) with nitriles under acidic conditions in moderate yields in a one-pot manner.
Generation and cyclization of nitrilium ions from amides. Asymmetric synthesis of fused azabicyclics
作者:Robert E. Gawley、Sanjay Chemburkar
DOI:10.1016/s0040-4039(00)84451-2
日期:1986.1
Treatment of 2° amides with PPSE affords nitrilium ions which may be cyclized onto appropriate terminators. The conditions are compatible with esters in the molecule, and further elaboration to pyrrolizidine and indolizidine rings is possible via asymmetric reduction.
Acyl derivatives of 4-phenyl-but-3-enylamine on treatment with phosphoryl chloride gave good yields of pyrrolines. Pyridine derivatives were not obtained.
Treatment of the di-2-[(IS)-1-(methylthio)ethyl]phenyl diselenide with bromine and silver triflate afforded the corresponding selenyl triflate which was used in situ as a strongly electrophilic selenium reagent to effect the asymmetric synthesis of oxygen- or nitrogen-containing heterocycles. Cyclic ethers, lactones, lactams or N-protected pyrrolidines have been prepared in good yield with complete regioselectivity and high diastereoselectivity. (C) 2001 Elsevier Science Ltd. All rights reserved.