An unprecedented enantioselective oxetane opening with chloride provides access to a range of highly functionalized three-carbon building blocks. The excellent enantiocontrol is enabled not only by a new catalyst, but also by the unusual use of wet molecular sieves for the controlled release of HCl.

A new asymmetric synthesis of chiral 1,4-dioxanes and other oxa-heterocycles has been developed by means of organocatalytic enantioselective desymmetrization of oxetanes. This mild process proceeds with exceedingly high efficiency and enantioselectivity to establish the quaternary stereocenters. This method complements the existing, yet limited, strategies for the synthesis of these oxa-heterocycles.

A new asymmetric synthesis of chiral 1,4-dioxanes and other oxa-heterocycles has been developed by means of organocatalytic enantioselective desymmetrization of oxetanes. This mild process proceeds with exceedingly high efficiency and enantioselectivity to establish the quaternary stereocenters. This method complements the existing, yet limited, strategies for the synthesis of these oxa-heterocycles.

An unprecedented enantioselective oxetane opening with chloride provides access to a range of highly functionalized three-carbon building blocks. The excellent enantiocontrol is enabled not only by a new catalyst, but also by the unusual use of wet molecular sieves for the controlled release of HCl.

The asymmetric fluorination of azolium enolates that are generated from readily available simple aliphatic aldehydes or α-chloro aldehydes and N-heterocyclic carbenes (NHCs) is described. The process significantly expands the synthetic utility of NHC-catalyzed fluorination and provides facile access to a wide range of α-fluoro esters, amides, and thioesters with excellent enantioselectivity. Pyrazole was identified as an excellent acyl transfer reagent for catalytic amide formation.

Described herein is a general and mild catalytic asymmetric 1,6-conjugate addition of para-quinone methides (p-QMs), a class of challenging reactions with previous limited success. Benefiting from chiral Brønsted acid catalysis, which allows in situ formation of p-QMs, our reaction expands the scope to general p-QMs with various substitution patterns. It also enables efficient intermolecular formation of all-carbon quaternary stereocenters with high enantioselectivity.

Described is an efficient catalytic asymmetric intermolecular CC bond-formation process to generate acyclic all-carbon quaternary stereocenters. The reactions overcome the unfavorable steric hindrance around reactive centers, and the competitive elimination (E1), to form a range of useful indole products with excellent efficiency and enantioselectivity.

The asymmetric fluorination of azolium enolates that are generated from readily available simple aliphatic aldehydes or α-chloro aldehydes and N-heterocyclic carbenes (NHCs) is described. The process significantly expands the synthetic utility of NHC-catalyzed fluorination and provides facile access to a wide range of α-fluoro esters, amides, and thioesters with excellent enantioselectivity. Pyrazole was identified as an excellent acyl transfer reagent for catalytic amide formation.

Described herein is a general and mild catalytic asymmetric 1,6-conjugate addition of para-quinone methides (p-QMs), a class of challenging reactions with previous limited success. Benefiting from chiral Brønsted acid catalysis, which allows in situ formation of p-QMs, our reaction expands the scope to general p-QMs with various substitution patterns. It also enables efficient intermolecular formation of all-carbon quaternary stereocenters with high enantioselectivity.

Described is an efficient catalytic asymmetric intermolecular CC bond-formation process to generate acyclic all-carbon quaternary stereocenters. The reactions overcome the unfavorable steric hindrance around reactive centers, and the competitive elimination (E1), to form a range of useful indole products with excellent efficiency and enantioselectivity.

An organocatalytic enantio- and diastereoselective formal [3+2] annulation between imines and 1,4-dithiane-2,5-diol is disclosed. The reaction provides rapid access to chiral thiazolidine-based molecules starting from a readily available catalyst and achiral starting materials.

Siloxy alkynes are a family of versatile species in organic synthesis. This account reviews the annulation reactions of siloxy alkynes for the synthesis of a variety of carbo- and heterocyclic products. With various dipolarophiles or dipolarophile-like reaction partners, siloxy alkynes are capable of forming small (three- to six-membered) rings. Recently, we have expanded the scope to the synthesis of medium- and large-ring lactones, enabled by the design of new amphoteric molecules as well as a new ring-expansion strategy. These annulation reactions provide not only practically useful syntheses of cyclic molecules, but also important understanding of the fundamental reactivity of siloxy alkynes.