Synthesis of Polysubstituted Pyrroles

Cross coupling metathesis reactions from two ethylenic compounds 4 and 5 easily led to Michael acceptors 6ab and 7a-b. Reaction of these compounds, or of enone 5', with p-toluenesulfonylmethyl isocyanide (TosMIC) provided the disubstituted pyrroles 9a-c and 10a-b. The analogous reaction of compounds 6a-b and 5', but in presence of Ph3SnCl, provided the trisubstituted pyrroles 11a-c. All of these compounds 9-11 were thus obtained in two steps only.