Application of Chromium-Arene Complexes in the Organic Synthesis. Efficient Synthesis of Stilbene Phytoalexins

Abstract

Planar chiral η6-arene-Cr(CO)3 complexes represent highly valuable building blocks for the diastereo- and enantioselective synthesis. Their employment as synthons offer new and unique opportunities for the stereoselective multistep synthesis of complex natural products. The strategy of novel efficient synthesis of stilbene phytoalexins was based on arene chromium chemistry and the chemical and stereochemical effects of the metal unit on the reactivity of complexed arene ligand and stereochemical features of such compounds. Two variants for the construction of the trans-stilbene and diarylethanol framework via facilitated benzylic deprotonation of an η6-benzene-Cr(CO)3 complex and subsequent coupling with para-anisaldehyde in an aldol-type or a Wittig–Horner reaction were suggested.