Wei-Wei Liao

Construction of highly functional quaternary carbon stereocenters via an organocatalytic tandem cyanation-allylic alkylation reaction.

The first tertiary amine-catalyzed tandem cyanation-allyic alkylation (CAA) reaction of aldehydes, appropriate cyanide sources, and Morita-Baylis-Hillman (MBH) adducts has been developed, which provides a facile access to densely functionalized products containing O-substituted quaternary centers.

Nucleophilic Phosphine-Catalyzed Intramolecular Michael Reactions of N-Allylic Substituted α-Amino Nitriles: Construction of Functionalized Pyrrolidine Rings via 5-endo-trig Cyclizations

Pyrrolidine rings are common moieties for pharmaceutical candidates and natural compounds, and the construction of these skeletons has received much attention. α-Amino nitriles are versatile intermediates in synthetic chemistry and have been widely used in the generation of multiple polyfunctional structures. Herein, a novel nucleophilic phosphine-catalyzed intramolecular Michael reaction of N-allylic substituted α-amino nitriles has been developed for the efficient construction of functionalized 2,4-disubstituted pyrrolidines (N-heterocyclic α-amino nitriles) via 5-endo-trig cyclization. Furthermore, the one-pot sequence of the synthesis of pyrrolidine and the subsequent transformations of the functionalized products have also been demonstrated.

Asymmetric Synthesis of Functionalized Dihydronaphthoquinones Containing Quaternary Carbon Centers via a Metal-Free Catalytic Intramolecular Acylcyanation of Activated Alkenes

A novel metal-free catalytic annulation was developed through a Lewis base-catalyzed asymmetric allylic alkylation and the ensuing unprecedented asymmetric intramolecular acylcyanation of alkenes. This protocol provides a unique and facile access to prepare enantioenriched densely functionalized dihydronaphthoquinones accompanied by enantiomerically pure 3,3-disubstituted phthalides bearing quaternary carbon centers.

Lewis base promoted intramolecular acylcyanation of α-substituted activated alkenes: construction of ketones bearing β-quaternary carbon centers.

A novel phosphine-promoted intramolecular acylcyanation of α-substituted activated alkenes has been developed, which provides a unique access to densely functionalized acyclic ketones bearing β-quaternary carbon centers with a remarkable feature that both α- and β-positions of activated alkene are functionalized.

Asymmetric Construction of Functionalized 1,2-Dihydropyridine and Pyridine Derivatives with Adjacent Stereocenters via a Unified Metal-Free Catalytic Approach

A novel asymmetric catalytic approach for the construction of enantioenriched functionalized 1,2-dihydropyridines and pyridine derivatives incorporating adjacent quaternary and tertiary stereocenters has been reported. This process involved a metal-free catalytic asymmetric allylic alkylation and a stereospecifically nonoxidative aromatization approach for the desired chiral molecules.

Copper-Promoted Cyclization of α-Amino Nitrile-Tethered Enynes: Controllable Synthesis of 3-Azabicyclo[4.1.0]hepta-2,4-dienes and 4,5-Dihydro-3H-azepines

The first example of Cu-promoted cyclization of α-amino nitrile-tethered enynes incorporating an electron-deficient alkene component is described. A wide range of functionalized 3-azabicyclo[4.1.0]hepta-2,4-dienes and 4,5-dihydro-3H-azepines were prepared efficiently in a controllable manner. Moreover, the diverse cascade process enables efficient incorporation of tertiary amine moieties under mild reaction conditions. A possible reaction pathway is proposed on the basis of a series of control experiments.

Asymmetric Synthesis of Dihydronaphthoquinones Containing Adjacent Stereocenters via a Sulfa-Michael Addition Triggered Ring-Expansion Approach.

A novel asymmetric synthetic approach for the construction of enantioenriched functionalized dihydroquinones incorporating adjacent quaternary and tertiary stereocenters has been reported, in which enantioenriched 3-allylic phthalides engaged in an unprecedented sulfa-Michael addition-triggered stereoselective ring-expansion reaction, and furnished the desired sulfur-incoporated dihydronaphthoquinones with high stereoselectivity.

Controllable Diastereodivergent Synthesis of Pyrrolo[2,1-a]isoquinolines via Catalytic Intramolecular Acylsulfenylation of Activated Alkenes

A controllable stereoselective synthesis of tetrahydropyrrolo[2,1-a]isoquinoline derivatives bearing a sulfur moiety was demonstrated with high diastereoselectivity through a catalytic intramolecular acylsulfenylation of activated alkenes. This approach involved a catalytic thia-Michael addition triggered intramolecular aldol-type tandem sequence. Both cis- and trans-products can be readily prepared in moderate to high yields with excellent diastereoselectivities in a catalytically atom-economic fashion under the optimized mild reaction conditions.

Lewis Base-Catalyzed One-Pot Cascade Sequences of O-Alkenyl-Substituted Cyanohydrins: Diastereoselective Synthesis of Multisubstituted Dihydrofurans

The first example of the diastereoselective construction of polysubstituted 2,3-dihydrofurans incorporating contiguous quaternary and tertiary carbon centers via a Lewis base-catalyzed one-pot cascade sequence is described. The diversity and complexity of the final products can be efficiently constructed with high diastereoselectivities via this catalytic multistep process under mild reaction conditions.

Lewis base-promoted rearrangement of allylic cyanohydrins: construction of functionalized nitriles bearing 1,3-diketone moieties.

A novel Lewis base-promoted rearrangement of allylic cyanohydrins has been developed, in which the cyano group was rearranged, directly coupled with the generation of new functional groups. This protocol provides a unique and facile way to prepare highly functionalized nitriles bearing 1,3-diketone moieties under mild reaction conditions. Furthermore, the synthetic transformations of the functionalized products have also been demonstrated.