Sulfenylnitrene-mediated aminative cyclizations for the diastereoselective synthesis of fused bicyclic indolines

We disclose the sulfenylnitrene-mediated synthesis of aminated, fused bicyclic indolines from tryptamine and tryptophol derivatives. This method provides rapid, metal-free access to valuable bioactive indoline scaffolds under operationally simple conditions. The approach accommodates a variety of nucleophiles including unprotected indoles, works in a variety of solvents, and provides access to 5, 6, and 7-membered bicycles. We have also demonstrated the scalability of our methodology through a gram scale synthesis.