Synthesis of 2-Phosphonopyrroles

Significance

A one-pot ring-closing metathesis (RCM) and oxidation sequence of functionalized α-aminoalkenyl phosphates to give 2-phosphono­pyrroles is reported. The starting α,β-unsaturated N-alkylaldimines were readily prepared in moderate yields by regioselective phosphorylation followed by N-benzylation. The RCM-oxidation sequence was performed under second generation Grubbs catalysis. Following tetrachloroquinone oxidation, the products were obtained in 70-84% yields (N-benzyl derivatives) and in 27-39% yields (N-unprotected derivatives).