Ling Chen

Bio: Ling Chen is an academic researcher from Jiangxi Normal University. The author has contributed to research in topics: Chirality (chemistry) & Enantioselective synthesis. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Nickel(0)-Catalyzed Asymmetric Ring Expansion Toward Enantioenriched Silicon-Stereogenic Benzosiloles.

Abstract: The development of a straightforward strategy to obtain enantioenriched silicon-stereogenic benzosiloles remains a challenging yet appealing synthesis venture due to their potential future application in chiral electronic and optoelectronic devices. In this context, all of the existing methods rely on Rh-catalyzed systems and are somewhat limited in scope. Herein, we disclose the first Ni0 -catalyzed ring expansion process that enables the preparation of benzosiloles possessing tetraorganosilicon stereocenters in excellent yields and enantioselectivities. The presented catalysis strategy is further applied to the asymmetric synthesis of silicon-stereogenic bis-silicon-bridged π-extended systems. Preliminary studies reveal that such compounds exhibit fluorescence emission, Cotton effects and circularly polarized luminescence (CPL) activity.

Enantioselective Intermolecular C-H Silylation of Heteroarenes for the Synthesis of Acyclic Si-Stereogenic Silanes.

Abstract: Intermolecular C-H silylation for the synthesis of acyclic silanes bearing silicon-stereogenic center in one enantiomeric form remains unknown to date. Herein, we report the first enantioselective intermolecular C-H silylation of heteroarenes for the synthesis of acyclic silicon-stereogenic heteroarylsilanes. This process undergoes a rhodium-catalyzed direct intermolecular dehydrogenative Si-H/C-H cross-coupling, giving access to a variety of acyclic heteroarylated silicon-stereogenic monohydrosilanes, including bis-Si-stereogenic silanes, in decent yields with excellent chemo -, regio -, and stereo -control, which significantly enlarge the chemical space of the optically active silicon-stereogenic monohydrosilanes.

Nickel(0)-catalyzed divergent reactions of silacyclobutanes with internal alkynes

Abstract: Transition metal-catalyzed reactions of silacyclobutanes with a variety of π units have attracted much attention and become one of the most straightforward and efficient approaches to rapidly access structurally diverse organosilicon compounds. However, the reaction of silacyclobutanes with alkynes still suffers from some limitations: (1) internal alkynes remain challenging substrates; (2) expensive Pd- or Rh-based catalysts have been employed in all existing systems; (3) controlling chemodivergence has not yet been realized. Herein we realize Ni-catalyzed chemodivergent reactions of silacyclobutanes with alkynes. In comparison with the previous Pd or Rh catalytic systems, our Ni-catalytic system features: 1) complementary substrate scope; 2) ligand-controlled chemodivergence; 3) low cost. The ligand precisely dictates the pathway selectivity, leading to the divergent formation of (benzo)silacyclohexenes and allyl vinylsilanes. Moreover, we demonstrate that employment of a chiral phosphine ligand is capable of forming silicon-stereogenic allyl vinylsilanes in high yields and enantioselectivities. In addition, DFT calculation is performed to elucidate the origin of the switchable selectivities, which is mainly attributed to different ligand steric effects.

Synthesis of Si-Stereogenic Silanols by Catalytic Asymmetric Hydrolytic Oxidation.

Abstract: Despite a growing progress for the construction of chiral organosilicon compounds, the catalytic asymmetric synthesis of silicon-stereogenic silanols is less explored and remains a considerable challenge. Herein, we report the first enantioselective construction of silicon-stereogenic silanols via catalytic asymmetric hydrolytic oxidation of dihydrosilanes. This practical protocol features ambient reaction conditions, high atom economy, good functional-group compatibility, and cleaner manner with H2 as the only by-product, producing a wide range of valuable chiral silanols and bis-silanols in decent yields with excellent chemo- and stereoselectivity.