Catalytic asymmetric addition of thiols to silyl glyoxylates for synthesis of multi-hetero-atom substituted carbon stereocenters

Abstract

Enantioselective addition of thiols to silyl glyoxylates for construction of a multi-hetero-atom substituted carbon stereocenter was described.

Rhodium‐Catalyzed Asymmetric Arylation‐Induced Glycolate Aldol Additions of Silyl Glyoxylates

“…Lanthanide iso‐ propoxides were competent hydride sources and turnover was uniquely enabled by alkoxide metathesis using a strain‐release Lewis acidic silacycle (Scheme 1c). Catalytic, asymmetric two‐component reactions of silyl glyoxylates have been reported that give non‐Brook rearranged products, [10–12] and absolute stereocontrol has also been achieved with a chiral auxiliary in the terminating electrophile [13] …”

“…[9] Lanthanide iso-propoxides were competent hydride sources and turnover was uniquely enabled by alkoxide metathesis using a strain-release Lewis acidic silacycle (Scheme 1c). Catalytic, asymmetric twocomponent reactions of silyl glyoxylates have been reported that give non-Brook rearranged products, [10][11][12] and absolute stereocontrol has also been achieved with a chiral auxiliary in the terminating electrophile. [13] An unsolved challenge suggested by this collective prior art is the inability to achieve useful three-component couplings: (i) with air-stable carbon pro-nucleophiles; (ii) catalyzed by substoichiometric quantities of a metal complex; and (iii) with absolute stereocontrol guided by the chiral catalyst.…”

Bimetallic tandem catalysis-enabled enantioselective cycloisomerization/carbonyl–ene reaction for construction of 5-oxazoylmethyl α-silyl alcohol

“… 3 Asymmetric nucleophilic addition to acylsilanes 4 containing an sp 2 carbon atom binding to both a silicon and an oxygen atom is one of the most direct and efficient accesses to optically active α-silyl alcohols ( Scheme 1a ), 4 and has attracted considerable attention in the past two decades. A series of intriguing studies were realized by several groups, wherein highly active nucleophilic reagents, such as organometallic reagents, 5 a – e , h enamine, 5 f enolate, 5 g or thiol, 5 i were commonly employed to offset the poor reactivity of the acylsilanes.…”

Non-enzymatic catalytic asymmetric cyanation of acylsilanes

“…Owing to the increasing interest in chiral silicon-containing molecules, such as silicon isosteres in drug design and development [35][36][37][38][39][40][41] and synthetic building blocks in stereocontrolled C-C bond formation and rearrangements [42][43][44][45] , there have been some recent reports on the catalytic asymmetric addition of carbon and heteroatom nucleophiles to acylsilanes [46][47][48][49][50][51][52] . However, among carbon nucleophiles, only alkylation and alkynylation have been reported to date (Fig.…”