Catalytic Asymmetric Dehydrogenative Si–H/X–H Coupling toward Si-Stereogenic Silanes DOI

Yicong Ge,

Jie Ke, Chuan He

et al.

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

ConspectusChiral organosilicon compounds bearing a Si-stereogenic center have attracted increasing attention in various scientific communities and appear to be topic of high current relevance modern organic chemistry, given their versatile utility as chiral building blocks, reagents, auxiliaries, catalysts. Historically, access these non-natural silanes mainly relies on resolution, whereas asymmetric synthetic methods dramatically lagged compared carbon counterparts. Over the past two decades, transition-metal-catalyzed desymmetrization prochiral organosilanes has emerged an effective tool for synthesis enantioenriched silanes. Despite progress, catalytic reactions usually suffer from limited substrate scope, poor functional-group tolerance, low enantioselectivity. The growing demand with structural diversity continued drive development new practical assembly molecules.Five years ago, our research group embarked project aimed at developing general approach that can unlock functionalized efficiency. This Account describes laboratory's endeavor exploration dehydrogenative Si–H/X–H coupling toward features (1) readily accessible dihydrosilane starting materials; (2) diverse X–H (X═C, N, O, etc.) partners; (3) platform transformable monohydrosilane products; (4) efficiency atomic economy.At initial stage research, biaryl was selected model conduct enantioselective intramolecular C–H/Si–H reaction. Rh/Josiphos system found early this process, while final enantiocontrol elusive. Mechanistic studies indicated rhodium silyl dihydride complex is resting state cycle, which may undergo racemization center. Enlightened by mechanistic investigations, strategies, tandem alkene hydrosilylation strategy bulky alkene-assisted strategy, were adopted avoid racemization, delivering corresponding 9-silafluorenes excellent yields enantioselectivities. Further C(sp2)–H or C(sp3)–H silylation gave series five-, six- seven-membered heterocycles Next, we extended reaction intermolecular version, realizing Si–H/C–H, Si–H/O–H, Si–H/N–H variety acyclic monohydrosilanes, ethers, siloxanes, silanols, silazanes. We also presented endeavors apply resulting compounds, including further derivatization, polymerization, chiroptical property successfully introduced Si-stereocenters into bioactive molecules, polymers, materials. Lastly, based understanding metal species, developed type ligand applied enable atroposelective anticipate methodology, insights, studies, will not only inspire chemistry but contribute creation novel molecules medicinal materials science.

Language: Английский

Catalytic Asymmetric Dehydrogenative Si–H/X–H Coupling toward Si-Stereogenic Silanes DOI

Yicong Ge,

Jie Ke, Chuan He

et al.

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

ConspectusChiral organosilicon compounds bearing a Si-stereogenic center have attracted increasing attention in various scientific communities and appear to be topic of high current relevance modern organic chemistry, given their versatile utility as chiral building blocks, reagents, auxiliaries, catalysts. Historically, access these non-natural silanes mainly relies on resolution, whereas asymmetric synthetic methods dramatically lagged compared carbon counterparts. Over the past two decades, transition-metal-catalyzed desymmetrization prochiral organosilanes has emerged an effective tool for synthesis enantioenriched silanes. Despite progress, catalytic reactions usually suffer from limited substrate scope, poor functional-group tolerance, low enantioselectivity. The growing demand with structural diversity continued drive development new practical assembly molecules.Five years ago, our research group embarked project aimed at developing general approach that can unlock functionalized efficiency. This Account describes laboratory's endeavor exploration dehydrogenative Si–H/X–H coupling toward features (1) readily accessible dihydrosilane starting materials; (2) diverse X–H (X═C, N, O, etc.) partners; (3) platform transformable monohydrosilane products; (4) efficiency atomic economy.At initial stage research, biaryl was selected model conduct enantioselective intramolecular C–H/Si–H reaction. Rh/Josiphos system found early this process, while final enantiocontrol elusive. Mechanistic studies indicated rhodium silyl dihydride complex is resting state cycle, which may undergo racemization center. Enlightened by mechanistic investigations, strategies, tandem alkene hydrosilylation strategy bulky alkene-assisted strategy, were adopted avoid racemization, delivering corresponding 9-silafluorenes excellent yields enantioselectivities. Further C(sp2)–H or C(sp3)–H silylation gave series five-, six- seven-membered heterocycles Next, we extended reaction intermolecular version, realizing Si–H/C–H, Si–H/O–H, Si–H/N–H variety acyclic monohydrosilanes, ethers, siloxanes, silanols, silazanes. We also presented endeavors apply resulting compounds, including further derivatization, polymerization, chiroptical property successfully introduced Si-stereocenters into bioactive molecules, polymers, materials. Lastly, based understanding metal species, developed type ligand applied enable atroposelective anticipate methodology, insights, studies, will not only inspire chemistry but contribute creation novel molecules medicinal materials science.

Language: Английский

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