Catalytic Intramolecular Acylsulfenylation of Activated Alkenes: Enantioselective Synthesis of 3,3-Disubstituted Quinoline-2,4-diones

An asymmetric intramolecular acylsulfenylation approach is presented. By combining catalytic amount of chiral amino diether (1<i>S,</i>2<i>S</i>)-<b>L6</b> and RSLi, a wide range of 3,3-disubstituted quinoline-2,4-dione derivatives incorporating all-carbon quaternary stereocenters could be accessed in excellent yields and enantioselectivities in a catalytically atom-economic fashion. The concept relies on an asymmetric SMA/aldol type sequence by employing thioester as a bifunctional carbonyl resource, which enabled the construction of the cyclic scaffolds smoothly

Catalytic Intramolecular Acylsulfenylation of Activated Alkenes: Enantioselective Synthesis of 3,3-Disubstituted Quinoline-2,4-diones

An asymmetric intramolecular acylsulfenylation approach is presented. By combining catalytic amount of chiral amino diether (1<i>S,</i>2<i>S</i>)-<b>L6</b> and RSLi, a wide range of 3,3-disubstituted quinoline-2,4-dione derivatives incorporating all-carbon quaternary stereocenters could be accessed in excellent yields and enantioselectivities in a catalytically atom-economic fashion. The concept relies on an asymmetric SMA/aldol type sequence by employing thioester as a bifunctional carbonyl resource, which enabled the construction of the cyclic scaffolds smoothly

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

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

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

Lewis Base-Catalyzed One-Pot Cascade Sequences of <i>O</i>‑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

Nucleophilic Phosphine-Catalyzed Intramolecular Michael Reactions of <i>N</i>‑Allylic Substituted α‑Amino Nitriles: Construction of Functionalized Pyrrolidine Rings via 5-<i>endo</i>-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 <i>N</i>-allylic substituted α-amino nitriles has been developed for the efficient construction of functionalized 2,4-disubstituted pyrrolidines (<i>N</i>-heterocyclic α-amino nitriles) via 5-<i>endo</i>-trig cyclization. Furthermore, the one-pot sequence of the synthesis of pyrrolidine and the subsequent transformations of the functionalized products have also been demonstrated

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