Enantioselective alkynylation of aromatic and heteroaromatic aldehydes catalyzed by resin-supported oxazolidine-titanium complexes

Highly enantioselective asymmetric addition of terminal alkynes to various aromatic and heteroaromatic aldehydes catalyzed by the readily available, low-cost, and reusable resin-supported oxazolidine 4 together with Ti((OPr)-Pr-i)(4) provides the chiral propargylic alcohols with good to excellent yields (up to 98%) and enantioselectivities (up to 95%). The immobilized catalyst can be recovered and used for five cycles. (C) 2008 Elsevier Ltd. All Fights reserved.