Catalytic asymmetric synthesis of (−)-E-δ-viniferin via an intramolecular C–H insertion of diaryldiazomethane using Rh2(S-TFPTTL)4

Abstract

An asymmetric synthesis of (−)-E-δ-viniferin, a trans-resveratrol dimer natural product containing a dihydrobenzofuran ring, has been achieved by exploiting a Rh(II)-catalyzed intramolecular C–H insertion reaction of a diaryldiazomethane derivative as a key step. The C–H insertion under catalysis by dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2(S-TFPTTL)4, provided the 2,3-diaryl-2,3-dihydrobenzofuran core structure with perfect cis diastereoselectivity and 96%ee.