Enantioselective [6 + 2]-Cycloaddition of Transient 3-Methide-3 H -pyrroles with 2-Vinylindoles under Chiral Brønsted Acid Catalysis.

An organocatalytic, highly diastereo- and enantioselective [6 + 2]-cycloaddition of 3-methide-3 H -pyrroles with 2-vinylindoles has been developed. This BINOL phosphoric acid-catalyzed reaction utilizes pyrrole-3-carbinols as precursors for the in situ generation of 3-methide-3 H -pyrroles to access densely substituted cyclopenta[ b ]pyrroles bearing three contiguous stereogenic centers as single diastereomers in good yields with excellent enantioselectivity.