Development of ProPhenol/Ti(IV) Catalyst for Asymmetric Hydroxylative Dearomatization of Naphthols

By development of ProPhenol/Ti(IV) catalysts, a catalytic enantioselective hydroxylative dearomatization of naphthols is achieved by using TBHP as a simple oxidative reagent. The side coordinative chain equipped on the C1-position of β-naphthols plays an important role for initiating this asymmetric hydroxylative reaction, which might be a result of the proper cocoordination effects to the titanium center in the catalyst. A reasonable catalytic cycle is proposed, the catalytic system is applied to a reasonable range of this type of phenolic compound, and related concise transformations are carried out.

A General Asymmetric Synthesis of (R)-Matsutakeol and Flavored Analogs

An efficient and practical synthetic route toward chiral matsutakeol and analogs was developed by asymmetric addition of terminal alkyne to aldehydes. (R)-matsutakeol and other flavored substances were feasibly synthesized from various alkylaldehydes in high yield (up to 49.5%, in three steps) and excellent enantiomeric excess (up to >99%). The protocols may serve as an alternative asymmetric synthetic method for active small-molecule library of natural fatty acid metabolites and analogs. These chiral allyl alcohols are prepared for food analysis and screening insect attractants.

Highly enantioselective addition of phenylethynylzinc to aldehydes catalyzed by chiral cyclopropane-based amino alcohols

The enantioselective addition of phenylethynylzinc to aldehydes catalyzed by a series of cyclopropane-based amino alcohol ligands 7 was investigated. The reactions afforded chiral propargylic alcohols in high yields (up to 96%) and with excellent enantioselectivities (up to 98% ee) under mild conditions. Furthermore, studies on the structural relationship show that the matching of the chiral center configuration is crucial to obtain the high enantioselectivity.

Synthesis studies on the lomaiviticin A aglycone core: development of a divergent, two-directional strategy

The enantiomer of the bicyclic lomaiviticin aglycone A core was prepared via a two-directional, divergent approach featuring (1) a double Ireland Claisen rearrangement to establish key core bonds with correct relative stereochemistry and (2) a double olefin metathesis reaction to deliver both cyclohexene rings of the target.