Palladium-Catalyzed Asymmetric Addition of Diarylphosphines to α,β-Unsaturated Sulfonic Esters for the Synthesis of Chiral Phosphine Sulfonate Compounds

Abstract

Highly stereoselective addition of diarylphosphines to α,β-unsaturated sulfonic esters catalyzed through a PCP pincer-Pd complex is developed to synthesize chiral phosphine sulfonic esters with excellent enantioselectivity (up to 99.5% ee). The transformation of the chiral adduct into a useful palladium phosphine sulfonate complex is also demonstrated.

Preparation of phosphines through C–P bond formation

“…In the proposed mechanism the catalyst 55 acts as a base toward the diarylphosphine 25c . Some other examples of palladium-catalyzed asymmetric hydrophosphination are the addition of diphenylphosphine to α,β-unsaturated ketones [127–128], esters [129], sulfonic esters [130] or to dienones [131]. The proposed mechanism is ubiquitous in metal-catalyzed hydrophosphination involving a P–H oxidative addition, insertion of the olefin into the Pd–H bond and reductive elimination.…”

Styrylsulfonates and ‐Sulfonamides through Pd‐Catalysed Matsuda–Heck Reactions of Vinylsulfonic Acid Derivatives and Arenediazonium Salts

“…One of the previously reported syntheses, of 2‐arylhomotaurines exploits the Michael‐acceptor reactivity of styrylsulfonates, which undergo conjugate addition of deprotonated nitromethane, followed by reduction of the nitro group to give a primary amine . Considerable efforts have been made over the past decade to render similar conjugate additions of nucleophiles to α,β‐unsaturated sulfones and sulfonic acid derivatives enantioselective . In Scheme , representative examples of synthetic transformations of vinylsulfonyl derivatives in general, and styrylsulfonyl derivatives in particular, are shown.…”

“…Synthetic routes to vinylsulfones, including some styrylsulfones, have been reviewed . Most syntheses rely on phosphonate‐based olefination reactions, an approach that can also be used for sulfonic acid esters and amides , , , . A stereoselective synthesis of Z ‐vinylsulfones by Peterson olefination has recently been reported .…”

“…[25] Considerable efforts have been made over the past decade to render similar conjugate additions of nucleophiles to α, -unsaturated sulfones and sulfonic acid derivatives enantioselective. [26][27][28][29][30][31] In Scheme 1, representative examples of synthetic transformations of vinylsulfonyl derivatives in general, and styrylsulfonyl derivatives in particular, are shown. Isoindole 12 results from the intramolecular conjugate addition of an amine to an α, -unsaturated sulfonamide.…”

“…[12] Most syntheses rely on phosphonate-based olefination reactions, an approach that can also be used for sulfonic acid esters and amides. [30,31,43,44] A stereoselective synthesis of Z-vinylsulfones by Peterson olefination has recently been reported. [45] Another group of syntheses proceeds through transition-metal-catalysed allylic substitutionisomerization sequences [46,47] or cross-coupling reactions [48,49] using sodium aryl sulfinates or sulfinate surrogates as nucleophiles.…”