Organocatalytic Enantioselective Aza-Michael Addition of Arylamines to 7-Methide-7H-Indoles

A chiral phosphorus acid catalyzed enantioselective 1,4-conjugate addition of arylamines to in situ formed 7-methylene-7H-indoles from 7-indolylmethanols has been developed for the first time. Without additives, the catalytic protocol enabled the formation of 1,4-adducts with a nitrogen-containing tertiary carbon stereocenter in 66-96% yield with 70-89% ee under mild conditions.

Automated summary

A chiral phosphorus acid catalyzed enantioselective 1,4-conjugate addition of arylamines to in situ formed 7-methylene-7H-indoles from 7-indolylmethanols has been successfully developed for the first time without the use of additives. The catalytic protocol enables the formation of 1,4-adducts with a nitrogen-containing tertiary carbon stereocenter in moderate to high yields and good enantioselectivity under mild reaction conditions.