Convenient synthesis of (E)-5-aminoallyl-2′-deoxycytidine and some related derivatives

Preparation via the Heck reaction of 5-(E)-(3-trifluoroacetamidoallyl)-2′-deoxycytidine (3a) and some N4-formamidine protected derivatives is reported. Difficulties with coupling N-allyl-trifluoroacetamide to 5-iodo-2′-deoxycytidine were overcome by using Pd2(dba)3 as catalyst and temporary dimethylformamidine protection of the N4-amine of the nucleoside. Compound 3a was isolated with 60% overall yield by crystallization.