Enantioselective bifunctional iminophosphorane catalyzed sulfa-Michael addition of alkyl thiols to unactivated β-substituted-α,β-unsaturated esters.

Enantioselective bifunctional iminophosphorane catalyzed sulfa-Michael addition of alkyl thiols to unactivated β-substituted-α,β-unsaturated esters† †Electronic supplementary information (ESI) available: Experimental procedures, spectroscopic data, copies of 1H and 13C NMR spectra and HPLC and GC chromatograms. See DOI: 10.1039/c6sc02878k Click here for additional data file.

Chiral squaramide-catalysed one-pot enantioselective sulfa-Michael addition/thioesterification of thiols with α,β-unsaturated N-acylated succinimides.

A novel highly enantioselective one-pot dithiolation through sulfa-Michael addition/thioesterification of thiols with α,β-unsaturated N-acylated succinimides catalysed by squaramide has been developed. This organocatalysed reaction proceeded well in high to excellent yields (up to >99%) to afford useful bioactive β-sulfated thioester derivatives with high enantioselectivities (up to 96% ee).

Bifunctional Iminophosphorane Organocatalysts for Enantioselective Synthesis: Application to the Ketimine Nitro-Mannich Reaction

The design, synthesis, and development of a new class of modular, strongly basic, and tunable bifunctional Brønsted base/H-bond-donor organocatalysts are reported. These catalysts incorporate a triaryliminophosphorane as the Brønsted basic moiety and are readily synthesized via a last step Staudinger reaction of a chiral organoazide and a triarylphosphine. Their application to the first general...

Aryloxide‐Facilitated Catalyst Turnover in Enantioselective α,β‐Unsaturated Acyl Ammonium Catalysis

A new general concept for α,β-unsaturated acyl ammonium catalysis is reported that uses p-nitrophenoxide release from an α,β-unsaturated p-nitrophenyl ester substrate to facilitate catalyst turnover. This method was used for the enantioselective isothiourea-catalyzed Michael addition of nitroalkanes to α,β-unsaturated p-nitrophenyl esters in generally good yield and with excellent enantioselect...

Enantioselective [3 + 2] annulation of α-substituted allenoates with β,γ-unsaturated N-sulfonylimines catalyzed by a bifunctional dipeptide phosphine

The first enantioselective [3 + 2] annulation of α-substituted allenoates with β,γ-unsaturated N-sulfonylimines is described. In the presence of a dipeptide phosphine catalyst, a wide range of highly functionalized cyclopentenes bearing an all-carbon quaternary center were obtained in moderate to good yields and with good to excellent enantioselectivities.