67533-31-7Relevant academic research and scientific papers
Rhodium-Catalyzed Regiodivergent Synthesis of Alkylboronates via Deoxygenative Hydroboration of Aryl Ketones: Mechanism and Origin of Selectivities
Zhang, Bing,Xu, Xin,Tao, Lei,Lin, Zhenyang,Zhao, Wanxiang
, p. 9495 - 9505 (2021/08/04)
Here, we report an efficient rhodium-catalyzed deoxygenative borylation of ketones to synthesize alkylboronates, in which the regioselectivity can be switched by the choice of the ligand. The linear alkylboronates were obtained exclusively in the presence of P(nBu)3, and PPh2Me favored the formation of branched alkylboronates. The protocol also allows access to 1,1,2-triboronates from the readily available ketones. Mechanistic studies suggest that this Rh-catalyzed deoxygenative borylation of ketones goes through an alkene intermediate, which undergoes regiodivergent hydroboration to afford linear and branched alkylboronates. The different steric effects of PPh2Me and P(nBu)3 were found to be responsible for product selectivity by density functional theory calculations. The alkene intermediate can alternatively undergo sequential dehydrogenative borylation and hydroboration to deliver the triboronates.
Zinc catalysed C3-H borylation of indoles and 1,1-diboration of terminal alkynes
Wang, Li,Zhang, Binfeng,Zhang, Hua,Zou, Youliang
supporting information, p. 11185 - 11188 (2021/11/04)
A low catalyst loading Zn(OTf)2-catalysed C3-H borylation of indoles with pinacolborane was developed. This transformation represents the use of an abundant, cheap and environmentally benign zinc catalyst in catalytic direct aromatic C-H borylation and offers a simple and prompt route towards the synthesis of C3-borylated indoles. The 1,1-diboration of terminal alkynes was also achieved using the same catalytic system to produce 1,1-diborylated alkenes.
Transborylation of alkenylboranes with diboranes
Bru, Gerard,Carbó, Jorge J.,Dominguez-Molano, Paula,Fernández, Elena,Maza, Ricardo J.,Salvado, Oriol
supporting information, p. 13361 - 13364 (2021/12/17)
Exchange of boryl moieties between alkenylboranes and diboron reagents has been postulated as a stereospecific cross-metathesis pathway with concomitant formation of mixed diboron reagents. DFT calculations propose a mechanism for the stereocontrolled C(sp2)-B/B′-B′ cross-metathesis with both symmetric and non-symmetric diboron reagents. This journal is
ZnBr2-Catalyzed Dehydrogenative Borylation of Terminal Alkynes
Luo, Man,Qin, Yi,Chen, Xi,Xiao, Qian,Zhao, Binlin,Yao, Weiwei,Ma, Mengtao
, p. 16666 - 16674 (2021/11/18)
The simple, commercially available ZnBr2 has been successfully employed as a highly efficient and chemoselective catalyst for the dehydrogenative borylation of terminal alkynes with HBpin under mild conditions. It shows a good tolerance toward various functional groups such as aryl, alkyl, heteroaryl, etc. The plausible reaction mechanism has been investigated based on the corresponding stoichiometric experiments and DFT calculations.
Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
, p. 18118 - 18127 (2020/11/26)
The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
Photoredox-Mediated Reaction of gem-Diborylalkenes: Reactivity Toward Diverse 1,1-Bisborylalkanes
Eghbarieh, Nadim,Kumar, Nivesh,Masarwa, Ahmad,Shames, Alexander I.,Stein, Tamar
, p. 5360 - 5364 (2020/04/23)
The use of gem-diborylalkenes as radical-reactive groups is explored for the first time. These reactions provide an efficient and general method for the photochemical conversion of gem-diborylalkenes to rapidly access 1,1-bisborylalkanes. This method expl
Selective Dehydrogenative Mono- or Diborylation of Styrenes by Supported Copper Catalysts
Yoshii, Daichi,Jin, Xiongjie,Mizuno, Noritaka,Yamaguchi, Kazuya
, p. 3011 - 3016 (2019/04/13)
The selective dehydrogenative borylation of alkenes is an attractive method for synthesizing useful borylalkenes. However, very few catalytic systems have been reported that fulfill this objective. All the reported examples are homogeneous catalysts with
Copper-Catalyzed Triboration: Straightforward, Atom-Economical Synthesis of 1,1,1-Triborylalkanes from Terminal Alkynes and HBpin
Liu, Xiaocui,Ming, Wenbo,Zhang, Yixiao,Friedrich, Alexandra,Marder, Todd B.
, p. 18923 - 18927 (2019/11/22)
A convenient and efficient one-step synthesis of 1,1,1-triborylalkanes was achieved via sequential dehydrogenative borylation and double hydroborations of terminal alkynes with HBpin (HBpin=pinacolborane) catalyzed by inexpensive and readily available Cu(OAc)2. This process proceeds under mild conditions, furnishing 1,1,1-tris(boronates) with wide substrate scope, excellent selectivity, and good functional-group tolerance, and is applicable to gram-scale synthesis without loss of yield. The 1,1,1-triborylalkanes can be used in the preparation of α-vinylboronates and borylated cyclic compounds, which are valuable but previously rare compounds. Different alkyl groups can be introduced stepwise via base-mediated deborylative alkylation to produce racemic tertiary alkyl boronates, which can be readily transformed into useful tertiary alcohols.
Catalytic Enantioselective Synthesis of 1,4-Keto-Alkenylboronate Esters and 1,4-Dicarbonyls
Liang, Michael Z.,Meek, Simon J.
supporting information, p. 14234 - 14239 (2019/08/30)
A catalytic enantioselective method for the synthesis of 1,4-keto-alkenylboronate esters by a rhodium-catalyzed conjugate addition pathway is disclosed. A variety of novel, bench-stable alkenyl gem-diboronate esters are synthesized. These easily accessible reagents react smoothly with a collection of cyclic α,β-unsaturated ketones, generating a new C?C bond and stereocenter. Products are isolated in up to 99 % yield with greater than 20:1 E/Z and greater than 99:1 e.r. Mechanistic studies show the site-selectivity of transmetalation and reactivity is ligand dependent. The utility of the approach is highlighted by gram-scale synthesis of enantioenriched cyclic 1,4-diketones, and stereoselective transformations of the products by hydrogenation, allylation, and isomerization.
Stereoselective Synthesis of Vinylboronates by Rh-Catalyzed Borylation of Stereoisomeric Mixtures
Li, Shenhuan,Li, Jie,Xia, Tianlai,Zhao, Wanxiang
, p. 462 - 468 (2019/03/28)
The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh-catalyzed borylation-isomerization sequence. The isomerization of (Z)-vinylboronates to (E)-isomers was also demonstrated.
