Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Allylic chlorides and phosphates reacted with alkyl-Grignard reagent in an S N 2′-selective manner in the presence of a catalytic amount of 1,2,3-triazol-5-ylidenes to provide α-branched alkenes. ... The S N 2′-selective Grignard-allylic substitution reactions were effectively catalyzed by ...