C-H center dot center dot center dot O hydrogen bond-directed ligand exchange reaction: Diastereoselective synthesis of P,S-bridged (mu-alkyne)Co-2(CO)(4) complexes

摘要

Here we describe a nonclassical interaction between a sulfonyl group in a dicobaltcarbonyl-alkyne complex and a methine moiety attached to three heteroatoms (O, P, S) included in the PuPHOS and CamPHOS ligands. This interaction provides an efficient recognition event that yields up to 86% de in the CO-phosphine exchange reaction. The isomerization mechanism leading to the observed diastereomeric bias was studied computationally at the semiempirical level.