very sensitive to moisture and the yields of ene products were low. N-(2,2,2-Trifluoro-1-ethoxyethyl)tosylamide (11), obtained by the reaction of trifluoroacetaldehyde ethyl hemiacetal (1) with tosylamide (3) in the presence of TiCl4 followed by addition of ethanol, was found to react as a good substitute for 4 to give the same products from the enereaction of 4 in much better yields.
Catalytic enantioselective addition of terminal 1,3-diynes to N-sulfonyl aldimines: access to chiral diynylated carbinamines
作者:Tian-Lin Liu、Heng-Xia Zhang、Yan Zheng、Qingwei Yao、Jun-An Ma
DOI:10.1039/c2cc37290h
日期:——
An efficient method for the asymmetric synthesis of chiral diynylated carbinamines is described. The direct catalytic enantioselective addition of terminal 1,3-diynes to N-sulfonyl aldimines proceeded smoothly under mild reaction conditions to produce diynylated carbinamines in up to 98% yield and 99% ee.