Modular Mo-based catalysts for efficient asymmetric olefin metathesis. Catalytic enantioselective synthesis of cyclic ethers and acetals

Chiral Mo-based complexes 1-3 promote the catalytic enantioselective ring-c losing metathesis of various polyenes to afford unsaturated furans, pyrans and siloxanes efficiently and in high ee (70-98% ee). The structural modula rity of this class of chiral catalysts plays a critical role in these studi es. Modification of the diolate or imido moities of these chiral catalysts gives rise to a range of complexes that can be screened for higher reactivi ty and/or enantioselectivity. (C) 2000 Elsevier Science Ltd. All rights res erved.