Concerted nucleophilic substitution reactions at sp 3 atoms are commonly encountered in mechanistic and synthetic organic chemistry. Although such a substitution reaction at a vinylic sp 2 carbon of unactivated vinyl halides rarely occurs, some examples were reported recently. For examples, 2-bromoallylamines were cyclized to aziridines by base treatment, and the stereospecificity of the cyclization reaction suggested that amino group approached from the backside of ...
