Triurethane-Protected Guanidines and Triflyldiurethane-Protected Guanidines: New Reagents for Guanidinylation Reactions

Abstract

New guanidinylation reagents are reported. These reagents consist of N,N‘,N‘‘-tri-Boc-guanidine (1) and N,N‘,N‘‘-tri-Cbz-guanidine (2), which allow for the facile conversion of alcohols to substituted guanidines. A series of arginine analogues were synthesized via condensation of a primary or secondary alcohol with the guanidinylation reagents 1 or 2, under Mitsunobu conditions,1 to produce protected alkylated guanidines. In addition, an extended study of the previously reported reagents2 N,N‘-di-Boc-N‘‘-triflylguanidine (3) and N,N‘-di-Cbz-N‘‘-triflylguanidine (4) is presented. The triflyldiurethane-protected guanidine 3 was utilized to guanidinylate primary and secondary amines under mild conditions with high yield in both solution and on solid phase.