Article
Chemistry, Multidisciplinary
Yankun Xu, Weiwei Xu, Xinyang Chen, Xiai Luo, Haiyan Lu, Minghao Zhang, Xiumei Yang, Guobo Deng, Yun Liang, Yuan Yang
Summary: A readily available disilane has been developed for the synthesis of diverse silacycles via Brook- and retro-Brook-type rearrangement, incorporating a silylene into various starting materials. Preliminary mechanistic studies suggest that this transformation involves successive palladium-catalyzed bis-silylation and rearrangement of silane-tethered silanols.
Article
Chemistry, Multidisciplinary
Yankun Xu, Mingjie Sun, Weiwei Xu, Guobo Deng, Yun Liang, Yuan Yang
Summary: A convenient silicon reagent (octamethyl-1,4-dioxacyclohexasilane) has been developed for the synthesis of various silacycles via time-controlled palladium-catalyzed cascade C-H silacyclization. Different ring sizes of silacycles, including benzodioxatetrasilecines, benzooxadisilepines, and benzosiloles, were obtained in moderate to good yields. Moreover, this reagent also enables the synthesis of diverse fused silacycles and various synthetic transformations of the products. Mechanistic studies reveal the transformation relationships and possible pathways among ten-, seven-, and five-membered silacycles.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Xi-Chao Wang, Hao-Ran Wang, Xiufang Xu, Dongbing Zhao
Summary: The paper discusses the significance of investigating sila-8-membered ring fused biaryls for the discovery of new drug lead compounds. It presents a method for synthesizing these compounds through chemo- and regio-selective cross-dimerization of 5-membered palladacycles with silacyclobutanes under Pd-catalytic conditions. This method provides an efficient route for ring expansion to create the desired sila-8-membered ring fused biaryl skeletons.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yafang Dong, Kohei Sekine, Yoichiro Kuninobu
Summary: Tribenzosilepins were synthesized efficiently from terphenyls and dihydrosilanes using a double sila-Friedel-Crafts reaction. The reaction system was capable of producing bidirectional silepin derivatives, and the transformation of amino groups to aryl groups as well as extension of the pi-system in tribenzosilepin were demonstrated.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Qing Wang, Kang-Bao Zhong, Hao Xu, Shi-Nan Li, Wei-Ke Zhu, Fei Ye, Zheng Xu, Yu Lan, Li-Wen Xu
Summary: Transition-metal-catalyzed silicon-carbon bond activation is an important process in organosilicon chemistry and homogeneous catalysis. This study reports a convenient and enantioselective Si-C bond cleavage-initiated [4 + 2] annulation, providing access to chiral six-membered oxasilacycles and their derivatives with high yields and enantioselectivities.
Article
Chemistry, Physical
Ming-Hui Zhu, Xiao-Wen Zhang, Muhammad Usman, Hengjiang Cong, Wen-Bo Liu
Summary: The construction of eight-membered silacycles through the Pd-catalyzed (4 + 4) annulation of silacyclobutanes and 2-iodobiphenyl derivatives involves direct C-H and C-Si bond activation followed by a ring annulation, with low catalyst loading, ligand-free conditions, and readily available starting materials. Mechanistic studies have revealed the involvement of five-membered palladacycle species in the reaction.
Article
Chemistry, Multidisciplinary
Jinyu Zhang, Deng Pan, Hao-Xiang Zhang, Nuo Yan, Xiao-Song Xue, Dongbing Zhao
Summary: The formal cross-dimerization of benzocyclobutenones (BCBs) and silacyclobutanes (SCBs) was achieved by a nickel/magnesium synergistic catalytic system, leading to the formation of eight-membered benzosilacycles. The reversal of site-selectivity in this reaction was attributed to the steric hindrance and the proper choice of catalyst.
Article
Chemistry, Physical
Xiaoxiao Tang, Yan Zhang, Yulang Tang, Yi Li, Jiajing Zhou, Duyang Wang, Lu Gao, Zhishan Su, Zhenlei Song
Summary: We report an efficient synthesis of exo-cyclic enoate-substituted silacyclohexenes by ring expansion of silacyclobutanes with allenoates. The reaction proceeds with two regioselectivities during Si-C bond insertion and can be catalyzed by Pd/PR3 or PtCl2 with different outcomes.
Article
Chemistry, Organic
Ryosuke Kondo, Hirokazu Moniwa, Ryo Shintani
Summary: A copper-catalyzed disilylative cyclization of silicon-containing internal alkynes with silylboronates has been developed for the synthesis of 3-silyl-1-silacyclopent-2-enes. The reaction proceeds regio- and anti-selectively under simple and mild conditions by employing a combination of nucleophilic silicon donors and electrophilic silicon acceptors. The reaction can also be extended to the synthesis of a 1-germacyclopent-2-ene and a silicon-centered spirocyclic compound using appropriate alkyne substrates.
Article
Chemistry, Organic
Jia-Hui Liu, Xue-Jiao Lv, Yan-Kai Liu
Summary: An asymmetric retro-Claisen reaction of alpha-mono-substituted beta-diketones and quinones (or quinone imine) has been developed using a chiral aza-bisoxazoline-Zn(II) complex as a catalyst. The reaction involves conjugate addition, arylation, hemiketal anion-initiated C-C bond cleavage, and enantioselective protonation of enolate, leading to the formation of functionalized alpha-arylated ketones with a tertiary stereogenic center in high enantioselectivities. Importantly, biologically significant benzofuran and gamma-butyrolactone derivatives can be synthesized using this protocol.
Article
Chemistry, Organic
Deyun Cui, Ying Feng, Yu Gan, Jiaqi Yin, Wanshu Wang, Yu Fan, Lu Gao, Bowen Ke, Zhenlei Song
Summary: 3-silaindolines were synthesized using 1,3-N,Si-tetraorganosilane reagents and arynes via a Cs2CO3-promoted (3 + 2)-annulation reaction. The reaction involved selective cleavage and formation of Si-C and Si-Ar bonds, allowing for further functionalization to expand the structural diversity of the products.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Hui Chen, Ranran Cui, Yahui Zhang, Yu Gao, Haijun Chen
Summary: In this study, a mild and metal-free synthesis of 3,3'-bisindoles is reported. The synthesis involves removal of the Fmoc group and subsequent cleavage of C-C and C-N bonds to generate the desired product. The resulting scaffold is suitable for further functionalization and exhibits interesting photophysical properties in both solution and solid state, suggesting its potential application in organic luminophores.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Tingting Li, Gerald B. Hammond, Bo Xu
Summary: A widely applicable approach to synthesize ketones, esters, and amides via the oxidative C-C bond cleavage of readily available alkyl aldehydes has been developed using green and abundant molecular oxygen as the oxidant, and base metals (cobalt and copper) as catalysts. This strategy can be extended to the one-pot synthesis of ketones from primary alcohols and alpha-ketoamides from aldehydes.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Yang Sik Yun, Claudia E. Berdugo-Diaz, David W. Flaherty
Summary: Biomass has received considerable attention as an alternative to petrochemicals in the production of valuable chemicals and fuels. This Perspective discusses significant advancements in understanding the reaction networks and mechanisms, reactive intermediates, and active site motifs for selective production of desired compounds through hydrogenolysis over heterogeneous catalysts. Continuing research into hydrogenolysis reactions faces current challenges and provides opportunities for future exploration.
Article
Chemistry, Organic
Chae Yeon Lee, Su Eun Lee, Hee Nam Lim
Summary: An SN1-type fluorination method for monofluoroethers is developed using oxygen-assisted Beckmann fragmentation to drive fluorinative C-C bond cleavage. Cyclic a-aryloxyoximes derived from 3-coumaranone and 1-indanones were investigated as substrates, with N,N-diethylamino-sulfur trifluoride (DAST) acting as a dual-role reagent of an oxime activator and fluoride donor. This method allows for the synthesis of an underdeveloped chemical motif under simple and mild operating conditions.
