R. Sustmann, M. Rogge
1990
Citations
0
Influential Citations
9
Citations
Journal
Tetrahedron Letters
Abstract
Abstract Reactions of 1,1 bis(N,N-dimethylamino)-1,3-butadiene ( 2 ) with acrylonitrile and tetracyanoethylene are described. At 80°C acrylonitrile affords a (4+2) cycloadduct ( 3 ), whereas a zwitterion ( 4 ), formed from 2 and tetracyanoethylene even at −40°C, is characterized in solution and trapped as picrate. It eliminates hydrogen cyanide at T>−20°C to give a cyanine ( 5 ). Ring closure of the zwitterion either to a (2+2) or to a (4+2) cycloaduct is not observed.