Catalytic addition of alkyne C-H, amine N-H, and phosphine P-Hbonds to carbodiimides: An efficient route to propiolamidines, guanidines, and phosphaguanidines

Various metal complexes (e. g., lanthanides, early transition metals, and alkali metals) can serve as catalyst precursors for the catalytic addition of alkyne C - H, amine N - H, and phosphine P - H bonds to carbodiimides, to give a new family of propiolamidines, guanidines, and phophaguanidines, some of which were difficult to prepare previously. The catalytic reaction proceeds generally through nucleophilic addition of an M - ER (E = (CRR2)-R-1, NR1, PR1) bond, which is formed by an acid - base reaction between a catalyst precursor and a RE - H bond, to a carbodiimide compound, followed by protonolysis of the resultant amidinate - (phospha) guanidinate species {R'NC(ER)NR'}M with RE - H.