Nickel-catalyzed enantioselective 1,2-vinylboration of styrenes

Abstract

A novel nickel-catalyzed asymmetric 1,2-vinylboration reaction has been developed to afford benzylic alkenylboration products with high yields and excellent enantioselectivities by using a chiral bisoxazoline ligand. Under optimized conditions, a...

Recent progress in nickel-catalyzed carboboration of alkenes

“…In 2021, our group developed a new nickel catalyzed enantioselective 1,2-vinylboration reaction to provide various benzylalkenylboration compounds with both excellent yields and enantioselectivities by employing a chiral bisoxazoline ligand. 34 Under the existing optimal reaction conditions, we tried to explore the universality of this three-component reaction. First, a number of ( E )-alkenyl bromides with electron-poor (ester, halides etc .)…”

Electronic Structures of Nickel(II)-Bis(indanyloxazoline)-dihalide Catalysts: Understanding Ligand Field Contributions That Promote C(sp2)–C(sp3) Cross-Coupling

“…To this end, we provide the first comprehensive spectroscopic and electrochemical investigation of two reductive cross-coupling catalysts, Ni II (IB)­Cl 2 and Ni II (IB)­Br 2 [ IB = (3a R ,3a′ R ,8a S ,8a′ S )-2,2′-(cyclopropane-1,1-diyl)­bis­(3a,8a-dihydro-8 H -indeno­[1,2- d ]-oxazole)], to provide broad insight into the complex conditions and mechanism (Scheme ). Although studies related to these complexes by one of our groups were primarily in the context of developing reductive alkenylation, we note that these and similar complexes have also been reported for a number of other reactions, including reductive arylation, 1,2-alkynylboration, and 1,2-vinylboration, further motivating their detailed experimental and computational investigations. − Here, we use variable-temperature (VT) UV–vis–NIR absorption, circular dichroism (CD), vibrational CD (VCD), and magnetic CD (MCD) spectroscopies, coupled with cyclic voltammetry, spectroelectrochemistry, and DFT/TDDFT and multireference (CASSCF/CASPT2) calculations to elucidate specific electronic structure contributions to reactivity, as well as the influence of solvent on the efficacy of catalytic transformations (Scheme ). Quantifying halide-dependent spectral features directly connects ligand field strength and redox potentials.…”

Electronic structures of nickel(II)-bis(indanyloxazoline)-dihalide catalysts: Understanding ligand field contributions that promote C(sp2)–C(sp3) cross-coupling

“…Although studies related to these complexes by one of our groups were primarily in the context of developing reductive alkenylation, we note that these and similar complexes have also been reported for a number of other reactions, including reductive arylation, 1,2-alkynylboration, and 1,2vinylboration, further motivating their detailed experimental and computational investigation. [21][22][23][24][25][26][27][28][29][30][31] Here we use variable-temperature (VT) UV-vis-NIR absorption, circular dichroism (CD), vibrational CD (VCD), and magnetic CD (MCD) spectroscopies, coupled with cyclic voltammetry, spectroelectrochemistry, and DFT/TDDFT and multi-reference (CASSCF/CASPT2) calculations to elucidate specific electronic structure contributions to reactivity, as well as the influence of solvent on the efficacy of catalytic transformations (Scheme 1). Quantifying halide-dependent spectral features directly connects ligand field strength and redox https://doi.org/10.26434/chemrxiv-2023-bkh36 ORCID: https://orcid.org/0000-0001-6026-1358 Content not peer-reviewed by ChemRxiv.…”