Enantioselective hydrophosphinylation of 1-alkenylphosphine oxides catalyzed by chiral strong Brønsted base

Synthesizing Chiral Vicinal Bisphosphine Derivatives through Hydrophosphinylation and Asymmetric Protonation of Secondary Phosphine Sulfides with Vinylphosphine Oxides

Herein, we report bifunctional iminophosphorane-catalyzed hydrophosphinylation and asymmetric protonation of secondary phosphine sulfides with vinylphosphine oxides. This reaction efficiently afforded chiral vicinal bisphosphine derivatives in high yields with excellent enantioselectivities (up to 99% yield and 95% ee). Furthermore, the produced chiral vicinal bisphosphine derivatives could be readily transformed into vicinal bisphosphines and vicinal bisphosphine monosulfides. This study presents the first methodology for using secondary phosphine sulfides as pronucleophiles in asymmetric protonation reactions.

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.

Construction of 1,3-Nonadjacent Stereogenic Centers Through Enantioselective Addition of α-Thioacetamides to α-Substituted Vinyl Sulfones Catalyzed by Chiral Strong Brønsted Base

An enantioselective addition reaction for the construction of 1,3-nonadjacent stereogenic centers is developed by means of a chiral strong Brønsted base catalyst. The chiral sodium ureate catalyst efficiently promoted the reaction of α-thioacetamides as less acidic pronucleophiles with vinyl sulfones having a variety of α-substituents including aryl, alkyl and halo groups, and α-phenylacrylates, accomplishing the construction of various 1,3-nonadjacent stereogenic centers in highly diastereo- and enantioselective manners. This is a rare example of the construction of 1,3-nonadjacent stereogenic centers with less acidic pronucleophiles. In addition, the application of Michael acceptors having various types of α-substituents in a single catalyst system is achieved for the first time, demonstrating the utility of the present catalyst system for the construction of 1,3-nonadjacent stereogenic centers.

Tunable vicinal, geminal diphosphorylation and C-N bond phosphorylation of enaminones toward divergent phosphorylated ketone derivatives

This paper reports the trifunctionalization reactions of tertiary enaminones in the fashion of selective gem- and vicinal diphosphorylation, leading to the tunable synthesis of α,α- and α,β-diphosphoryl ketones. In addition, the C-N bond phosphorylation with improved substrate tolerance has been achieved.

Development of chiral potassium strong Brønsted base catalysts for enantioselective carbon-carbon bond-forming reactions

Chiral alkaline metal Brønsted bases are traditional and reliable promoters in enantioselective catalysis. Here, new chiral potassium strong base catalysts were developed for enantioselective carbon-carbon bond-forming reactions of weakly acidic carbon pronucleophiles. Chiral potassium amide or alkyl potassium catalyzed enantioselective addition reactions to imines or α,β-unsaturated amides with good to high enantioselectivities. The good potential of chiral potassium Brønsted bases to act as proton transfer catalysts has been shown.