Synthesis and reactivity of alkenyl- and alkynyl-substituted β,β-dihalo-and β,β,β-trichloroamines
摘要:
beta,beta-Dihalo and beta,beta,beta-trichloroamines, obtained by Lewis acid-promoted Petasis-type reaction of alpha,alpha-dichlorinated and alpha,alpha,alpha-trichlorinated imines or reduction of alpha,alpha-dihaloaldimines, were subjected to a reactivity study and turned out to be remarkably stable compounds. In general, only the bases KO'Bu and NaOMe cause a 1,2-dehydrochlorination with formation of unsaturated alpha-chloroimines Or Unsaturated alpha,alpha-dichloroimines. Hydrolysis of the alpha-chloroimines with aqueous oxalic acid resulted in the formation of the corresponding unsaturated alpha-chloroketones. The reaction of simple beta,beta-dihaloamines with NaOMe and KO'Bu generated 2-haloprop-2-enylmines and 2,2-dimethoxypropylamines. (C) 2009 Elsevier Ltd. All rights reserved.
Lewis acid promoted Mannich type reactions of α,α-dichloro aldimines with potassium organotrifluoroborates
作者:Sara Stas、Kourosch Abbaspour Tehrani
DOI:10.1016/j.tet.2007.06.003
日期:2007.9
Potassium phenylethynyltrifluoroborate and potassium styryltrifluoroborates react with α,α-dichlorinated aldimines in the presence of BF3·OEt2 as a Lewis acid to give a new stable class of functionalized propargylamines and allylamines. The use of hexafluoroisopropanol as a co-solvent in this modified Petasis reaction allows high yield isolation of the target compounds.