57002-01-4Relevant academic research and scientific papers
A relay catalysis strategy for enantioselective nickel-catalyzed migratory hydroarylation forming chiral α-aryl alkylboronates
Chen, Jian,Liang, Yong,Ma, Jiawei,Meng, Lingpu,Zhang, Yao,Zhu, Shaolin
supporting information, p. 3171 - 3188 (2021/11/16)
Ligand-controlled reactivity plays an important role in transition-metal catalysis, enabling a vast number of efficient transformations to be discovered and developed. However, a single ligand is generally used to promote all steps of the catalytic cycle (e.g., oxidative addition, reductive elimination), a requirement that makes ligand design challenging and limits its generality, especially in relay asymmetric transformations. We hypothesized that multiple ligands with a metal center might be used to sequentially promote multiple catalytic steps, thereby combining complementary catalytic reactivities through a simple combination of simple ligands. With this relay catalysis strategy (L/L?), we report here the first highly regio- and enantioselective remote hydroarylation process. By synergistic combination of a known chain-walking ligand and a simple asymmetric cross-coupling ligand with the nickel catalyst, enantioenriched α-aryl alkylboronates could be rapidly obtained as versatile synthetic intermediates through this formal asymmetric remote C(sp3)-H arylation process.
Transition-Metal-Free C(sp2)–C(sp2) Cross-Coupling of Diazo Quinones with Catechol Boronic Esters
Che, Chi-Ming,Wu, Kai,Wu, Liang-Liang,Zhou, Cong-Ying
supporting information, p. 16202 - 16208 (2020/07/17)
A transition-metal-free C(sp2)?C(sp2) bond formation reaction by the cross-coupling of diazo quinones with catechol boronic esters was developed. With this protocol, a variety of biaryls and alkenyl phenols were obtained in good to high yields under mild conditions. The reaction tolerates various functionalities and is applicable to the derivatization of pharmaceuticals and natural products. The synthetic utility of the method was demonstrated by the short synthesis of multi-substituted triphenylenes and three bioactive natural products, honokiol, moracin M, and stemofuran A. Mechanistic studies and density functional theory (DFT) calculations revealed that the reaction involves attack of the boronic ester by a singlet quinone carbene followed by a 1,2-rearrangement through a stepwise mechanism.
Cobalt-Catalyzed Diastereo- and Enantioselective Hydroalkenylation of Cyclopropenes with Alkenylboronic Acids
Zhang, Haiyan,Huang, Wei,Wang, Tongtong,Meng, Fanke
supporting information, p. 11049 - 11053 (2019/07/17)
Catalytic diastereo- and enantioselective hydroalkenylation of 3,3-disubstituted cyclopropenes with readily accessible alkenylboronic acids, promoted by a chiral phosphine/Co complex, is presented. Such a process constitutes the unprecedented and direct i
Synthesis of α-Borylated Ketones by Regioselective Wacker Oxidation of Alkenylboronates
Corless, Victoria B.,Holownia, Aleksandra,Foy, Hayden,Mendoza-Sanchez, Rodrigo,Adachi, Shinya,Dudding, Travis,Yudin, Andrei K.
supporting information, p. 5300 - 5303 (2018/09/12)
As part of a program aimed at metal-catalyzed oxidative transformations of molecules with carbon-metalloid bonds, the synthesis of α-borylated ketones is reported via regioselective TBHP-mediated Wacker-type oxidation of N-methyliminodiacetic acid (MIDA)-protected alkenylboronates. The observed regioselectivity correlates with the hemilabile nature of the B-N dative bond in the MIDA boronate functional group, which allows boron to guide selectivity through a neighboring group effect.
A Tunable Route to Prepare α,β-Unsaturated Esters and α,β-Unsaturated-γ-Keto Esters through Copper-Catalyzed Coupling of Alkenyl Boronic Acids with Phosphorus Ylides
Bi, Hong-Yan,Liu, Feng-Ping,Liang, Cui,Su, Gui-Fa,Mo, Dong-Liang
supporting information, p. 1510 - 1516 (2018/03/05)
A tunable strategy to prepare α,β-unsaturated esters and α,β-unsaturated-γ-keto esters in good to excellent yields was developed through copper-catalyzed oxidative coupling of phosphorus ylides with alkenyl boronic acids under mild conditions. The reaction without water afforded α,β-unsaturated esters, ketones, and amides while α,β-unsaturated-γ-keto esters, 1,4-α,β-unsaturated diketones and α,β-unsaturated-γ-keto amides were obtained when using 5.0 equiv. of water. H2O18 labeling experiments showed that water played an important role in the formation of α,β-unsaturated-γ-keto esters. A plausible formation mechanism for α,β-unsaturated esters and α,β-unsaturated-γ-keto esters was proposed based on mechanistic studies. Phosphonium salts could also be used directly as coupling partners instead of phosphorus ylides. The reaction exhibited a broad substrate scope, good functional group tolerance, good regioselectivity, and diverse coupling products. (Figure presented.).
Oxalyl Boronates Enable Modular Synthesis of Bioactive Imidazoles
Lee, C. Frank,Holownia, Aleksandra,Bennett, James M.,Elkins, Jonathan M.,St. Denis, Jeffrey D.,Adachi, Shinya,Yudin, Andrei K.
supporting information, p. 6264 - 6267 (2017/05/19)
Described herein is the preparation of oxalyl boronate building blocks and their application for the construction of heterocycles. The oxalyl unit, readily accessible through commercially available starting materials, enables a modular approach for the synthesis of imidazoles. A variety of aromatic, heteroaromatic, and alkyl carboxaldehydes were condensed with oxalyl boronates to afford substituted boryl imidazoles in a regiocontrolled fashion. Subsequent palladium-catalyzed cross-coupling with haloarenes furnished the desired trisubstituted imidazole scaffolds. To demonstrate the utility of these scaffolds, potent inhibitors of the serine/threonine-protein kinase STK10 were synthesized.
Asymmetric Synthesis of α-Aminoboronic Acid Derivatives by Copper-Catalyzed Enantioselective Hydroamination
Nishikawa, Daiki,Hirano, Koji,Miura, Masahiro
supporting information, p. 15620 - 15623 (2016/01/09)
A copper-catalyzed regio- and enantioselective hydroamination of alkenyl dan boronates (dan =1,8-diaminonaphthyl) with hydrosilanes and hydroxylamines proceeds to deliver the chiral α-aminoboronic acids in good yields with high enantiomeric ratios. The ke
Rhodium(III)-catalyzed cross-coupling of alkenylboronic acids and N -pivaloyloxylamides
Feng, Chao,Loh, Teck-Peng
supporting information, p. 3444 - 3447 (2014/07/21)
Rh(III)-catalyzed umpolung amidation of alkenylboronic acids for the synthesis of enamides is reported. This reaction proceeds readily at room temperature and displays an extremely wide spectrum of functional group tolerance. With cooperation of hydrobora
