Asymmetric ring-closing metathesis with a twist.
A double flip! The catalyst shown, with a molybdenum stereocenter and monodentate ligands (Si = SitBuMe(2)), promotes asymmetric ring-closing metathesis of a broad range of substrates. Its unprecedented activity originates from its structural fluxionality, which enables double inversion at the metal center in the course of a single catalytic cycle. The catalyst passed the test in a metathesis reaction en route to (+)-quebrachamine (see scheme).
Klare
Hendrik F T
HF
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
Oestreich
Martin
M