Chiral Sulfinamide Bisphosphine Catalysts: Design, Synthesis, and Application in Highly Enantioselective Intermolecular Cross‐Rauhut–Currier Reactions

Abstract

A novel type of highly efficient chiral sulfinamide bisphosphine catalysts (Wei-Phos) were developed. These could be easily prepared from commercially available starting materials. Wei-Phos has shown good performance in the very challenging intermolecular cross-Rauhut-Currier reactions of vinyl ketones and 3-acyl acrylates or 2-ene-1,4-diones, leading to the R-C products in high yields with up to 99% ee under 2.5-5 mol% catalyst loading. The highly regio- and enantio-selective cross-Rauhut-Currier reactions of 2-ene-1,4-diones and vinyl ketone have yet reported so far.

Enantioselective Rauhut–Currier‐Type 1,6‐Conjugate Addition of Methyl Vinyl Ketone to para‐Quinone Methides

“…In 2014, Huang and co‐workers developed an enantioselective cross‐RC reaction between vinyl ketones and 3‐aroyl acrylates . Recently, Zhang's group demonstrated the cross‐RC reactions of vinyl ketones/acrolein with 3‐acyl acrylates or 2‐ene‐1,4‐diones –. It is worth noting that conventional second Michael acceptors were used in these enantioselective intermolecular RC reactions (Scheme a).…”

Access to P-chiral sec- and tert-phosphine oxides enabled by Le-Phos-catalyzed asymmetric kinetic resolution

“…and racemic mesityl(phenyl)phosphine oxide 1a in the presence of multifunctional chiral phosphine catalyst P1 (Wei-Phos, 10 mol%) in toluene (Table 1, entry 1). 10 The reaction gave the desired allylation product 3aa in 34% yield with 7% ee, along with recovered 1a in 30% yield with 17% ee, correlating with an s-factor of 1.3. Then, Xiao-Phos P2 was tested but a little better result was obtained (Table 1, entry 2).…”

Enantioselective N‐Heterocyclic Carbene Catalyzed Bis(enoate) Rauhut–Currier Reaction

“…While bis(enone) substrates (e.g., 2 a ) are generally well handled, less electrophilic enoate‐enones (e.g., 2 b ) and bis(enoate) substrates are more challenging. For example, phosphine 4 converts bis(enone) 2 a into cyclohexene 3 a , while under identical conditions, enoate‐enone 2 b is unreactive (Scheme b) . In cases where enoate‐enone substrates are viable, the enoate is β‐unsubstituted (e.g., 5 ; Scheme c), while to the best of our knowledge, bis(enoate) substrates are yet to be exploited in enantioselective RC reactions.…”