Catalyst-Controlled Asymmetric Chemodivergent Reaction of C,N-Cyclic Azomethine Imines with 2-Indolylacetates.

A catalyst-controlled asymmetric chemodivergent reaction of C,N-cyclic azomethine imines with 2-indolylacetates has been developed. By simply switching the chiral isothiourea catalyst, the reaction proceeds via either a catalytic asymmetric (3 + 2) cycloaddition or an addition reaction in a chemodivergent manner, affording two distinct families of chiral indole-based hydroisoquinolines in high yields (up to 90%) with excellent stereoselectivities (up to 99% ee). This work not only represents the first catalytic asymmetric chemodivergent reaction of C,N-cyclic azomethine imines but also serves as an excellent example of catalyst-controlled chemodivergent enantioselective transformation. Furthermore, it demonstrates a new application of 2-indolylacetates as reaction partners displaying either α- or γ-selectivity, thereby offering a powerful strategy for the synthesis of enantioenriched indole-based hydroisoquinolines.