Catalytic Divergent Synthesis of 3<i>H</i> or 1<i>H</i> Pyrroles by [3 + 2] Cyclization of Allenoates with Activated Isocyanides

The
cyclization of allenoates with activated isocyanides was reported
for the first time. While Ag catalysis led to an unprecedented enantioselective
synthesis of 3H pyrroles, a simple procedure using
PPh3 produced a wide range of polysubstituted 1H pyrroles with high efficiency.