Enantioselective Nucleophilic Vinylic Substitution (SNV) toward 3-Alkenyl-bisoxindoles Facilitated by C6' Steric Bulk of Cinchona Alkaloid

Construction of arylthio/arylamino methylene bonds by addition-elimination of nitroolefins with aromatic thiols and amines

A highly efficient, catalyst-free, metal-free, atom economical green protocol for the synthesis of arylthio/arylamino methylene compounds by a Michael attack of arylthiols and anilines on nitroolefins derived from acenaphthaquinone and isatin has been developed. The method needs methanol as a reaction solvent and does not require any recrystallization, work-up process or column chromatography. (E)-Arylthio alkenes and (Z)-arylamino alkenes were obtained as the sole products. The results obtained from computational studies using density functional theory on ORCA program (B3LYP/def2-SVP level) are in good agreement with the data obtained from the single crystal X-ray analysis.

Organocatalyzed Synthesis of γ-Alkenyl Butenolides via Asymmetric Direct Vinylogous Conjugate Addition-Elimination of Substituted Furanone Derivatives to β-Phenylsulfonylenones

A diaminomethylenemalononitrile organocatalyst efficiently promoted the asymmetric direct vinylogous conjugate addition of α-angelica lactone derivatives to β-phenylsulfonylenones, affording the corresponding γ-alkenyl γ-butenolides in high yields with excellent enantioselectivities (up to 97% ee) after the elimination of the phenylsulfonyl group. This study reports the first successful example of a stereoselective reaction using β-phenylsulfonylenone as the direct alkenyl donor.

Chiral Phosphine Ligands of COAP and SKP Switched Regiodivergent Asymmetric Allylic Alkylation of MBH Adducts

The palladium-catalyzed highly regioselective asymmetric allylic alkylation of 3'-indolyl-3-oxindole derivatives with Morita-Baylis-Hillman (MBH) carbonates was developed to facilely construct chiral 3,3'-bisindole derivatives under mild reaction conditions. The regioselectivity (α/γ) of MBH carbonates was efficiently switched in the presence of chiral oxalamide phosphine or spiroketal-based diphosphine/Pd(0) complexes as a chiral catalyst. A series of multifunctional 3,3'-bisindole derivatives with all-carbon quaternary stereogenic centers were obtained in high yields with good to excellent enantio-, diastereo-, and regioselectivity. The present process is endowed with some salient features such as broad substrate scope, N-protecting group-free, excellent stereoselectivity, as well as adjustable regioselectivity.

Regioselective One-Pot Synthesis of Vicinal Bisphosphine Derivatives from Nitroalkenes by Hydrophosphinylation/Elimination/Hydrophosphinylation

Herein, a facile method is developed for the synthesis of vicinal bisphosphine derivatives based on a cascade of hydrophosphinylation, elimination, and hydrophosphinylation of secondary phosphine oxides with nitroalkenes. This cascade reaction provides step-economy access to a series of vicinal bisphosphine derivatives with high to excellent yields (up to 99%). This method was further extended to prepare, in one-pot, regioselective vicinal bisphosphine derivatives that incorporated two different phosphorus functional groups.