Isothiourea-Catalyzed Acylative Desymmetrization of Silicon-Centered Bisphenols

Abstract

The preparation of optically pure organosilicon compounds bearing a stereogenic center at the silicon atom is an attractive but challenging enterprise. Herein we disclose an isothiourea (ITU)-catalyzed monoacylation reaction of silicon-centered bisphenols with 2,2-diphenylacetic pivalic anhydride, delivering tetrasubstituted organosilanes in moderate to excellent yields (36–91%) with moderate to excellent enantiomeric ratios (68:32–97.5:2.5). This organocatalytic desymmetrization approach can be performed on gram scale, and the products can be converted to other valuable compounds.

Pyridine-N-oxide catalyzed acylative desymmetrization of bisphenols: access to P-stereogenic phosphinates with low catalyst loadings

“…2 The construction of phosphorus chiral compounds mainly involves resolution techniques, 3 stereocontrol using chiral auxiliary agents, 4 metal-catalyzed asymmetric cross-coupling, 5 asymmetric addition reactions of phosphorus nucleophiles 6 and desymmetrization of prochiral phosphorus derivatives. 7–11 The separation of diastereoisomers and the synthesis of P-stereogenic compounds using chiral auxiliary agents greatly limit the scope of synthesis. Moreover, there have been few reports on strategies for constructing P-stereogenic compounds through organocatalysis.…”

“…Acylative desymmetrization reaction is a good strategy for constructing chiral centers. 11 In 2017, Spivey and co-workers pioneered the application of chiral DMAP- N -oxide catalysts 12,13 in enantioselective N -sulfonylation. 14 Based on our recent work on chiral DMAP- N -oxides and 4-aryl-pyridine- N -oxides (ArPNO) as acyl transfer catalysts, 15 we considered that chiral pyridine- N -oxides could be used as acyl transfer catalysts for the acylative desymmetrization of bisphenols, providing a highly efficient method for obtaining P-stereogenic phosphinates (Scheme 1d).…”

Bifunctional Thiourea-Catalyzed Enantioselective Aza-Friedel–Crafts Reaction of 3-Aminobenzofurans with Isatin-Derived Ketimines

“…However, to the best of our knowledge, the corresponding nucleophilic addition of 3-aminobenzofurans to C–N double bonds remains a challenge to be overcome. Our group is keen on the development of elegant approaches for constructing valuable molecules via asymmetric organocatalysis . Previously we have used isatin-derived ketimines ,, and 3-aminobenzofurans , as facile substrates to produce diversely functionalized heterocycles.…”

Research Progress on New Catalytic Reaction Systems for Asymmetric Synthesis of Silicon-Stereogenic Center Containing Compounds

“…Heterocyclic carbene-catalyzed desymmetrization of silicon-bridged dibenzaldehydes 图式 75 NHC 催化硅桥连二醛的单酯化反应 Scheme 75 N-Heterocyclic carbene-catalyzed monoesterification of silicone-bridged dialdehydes 图式 76 NHC 催化二醛分子内安息香缩合反应 Scheme 76 Carbene-catalyzed desymmetric benzoin reaction of siladials2023 年, 许建峰课题组[86] 报道了异硫脲催化硅桥 连双酚与 2,2-二苯基乙酸特戊酸酐的酰化反应. 如 Scheme 77 所示, 在手性异硫脲(ITU)的催化作用下, 前…”