Dual Rh(II)/Pd(0) Relay Catalysis Involving Sigmatropic Rearrangement Using N-Sulfonyl Triazoles and 2-Hydroxymethylallyl Carbonates

Dual Rh(II)/Pd(0) relay catalysis of N-sulfonyl triazoles and 2-hydroxymethylallyl carbonates has been developed, which affords N-sulfonyl pyrrolidines in moderate to good yields with high diastereoselectivities. The reaction proceeds via a relay mechanism involving O-H insertion onto the α-imino Rh(II)-carbene, [3,3]-sigmatropic rearrangement, dipole formation through Pd(0)-catalyzed decarboxylation, and intramolecular N-allylation, leading to the formation of multiple bonds in a one-pot operation.

The synthesis of indole-3-carbinols (I3C) and their application to access unsymmetrical bis(3-indolyl)methanes (BIMs) bearing a quaternary sp3-carbon

In the present study, the novel synthesis of tert-indole-3-carbinols is reported through the DDQ-mediated oxidation of the allylic C-H bond/aromatization/hydroxylation at the indolyl carbon using water as the hydroxyl source. The reaction is highly efficient and high yielding and it works under mild reaction conditions. Furthermore, the synthetic value of such indole-based tert-carbinols is explored through their use as excellent electrophilic methylene surrogates to develop medicinally important unsymmetrical bis(3-indolyl)methanes containing an all carbon quaternary center.