38050-71-4Relevant articles and documents
Hydroboration of carbon dioxide enabled by molecular zinc dihydrides
Chang, Kejian,Wang, Xiaoming,Xu, Xin
, p. 7324 - 7327 (2020)
Neutral molecular zinc(ii) dihydrides supported by N-heterocyclic carbene ligands bearing a pendant phosphine group were synthesized and then reacted with carbon dioxide to afford zinc diformates. The zinc dihydrides were found to be active catalysts for hydroboration of carbon dioxide under mild conditions, selectively giving boryl formate, bis(boryl)acetal, or methoxy borane compounds by changing the nature of the borane reductant.
Catalytic properties of nickel bis(phosphinite) pincer complexes in the reduction of CO2 to methanol derivatives
Chakraborty, Sumit,Patel, Yogi J.,Krause, Jeanette A.,Guan, Hairong
, p. 30 - 34 (2012)
A new nickel bis(phosphinite) pincer complex [2,6-(R2PO) 2C6H3]NiCl (LRNiCl, R = cyclopentyl) has been prepared in one pot from resorcinol, ClP(C5H 9)2, NiCl2, and 4-dimethylaminopyridine. The reaction of this pincer compound with LiAlH4 produces a nickel hydride complex, which is capable of reducing CO2 rapidly at room temperature to give a nickel formate complex. X-ray structures of two related nickel formate complexes LRNiOCHO (R = cyclopentyl and isopropyl) have shown an "in plane" conformation of the formato group with respect to the coordination plane. The stoichiometric reaction of nickel formate complexes LRNiOCHO (R = cyclopentyl, isopropyl, and tert-butyl) with catecholborane has suggested that the reaction is favored by a bulky R group. LRNiOCHO (R = tert-butyl) does not react with PhSiH3 at room temperature; however, it reacts with 9-borabicyclo[3.3.1]nonane and pinacolborane to generate a methanol derivative and a boryl formate species, respectively. The catalytic reduction of CO2 with catecholborane is more effectively catalyzed by a more sterically hindered nickel pincer hydride complex with bulky R groups on the phosphorus donor atoms. The nickel pincer hydride complexes are inactive catalysts for the hydrosilylation of CO 2 with PhSiH3.
A N-Phosphinoamidinato NHC-Diborene Catalyst for Hydroboration
Fan, Jun,Mah, Jian-Qiang,Yang, Ming-Chung,Su, Ming-Der,So, Cheuk-Wai
, p. 4993 - 5002 (2021/02/01)
The use of the N-phosphinoamidinato NHC-diborene catalyst 2 for hydroboration is described. The N-phosphinoamidine tBu2PN(H)C(Ph)= N(2,6-iPr2C6H3) was reacted with nBuLi in Et2O to afford the lithium derivative, which was then treated with B2Br4(SMe2)2 in toluene to form the N-phosphinoamidinate-bridged diborane 1. It was reacted with the N-heterocyclic carbene IMe (:C{N(CH3)C(CH3)}2) and excess potassium graphite at room temperature in toluene to give the N-phosphinoamidinato NHC-diborene compound 2. It can stoichiometrically activate ammonia-borane and carbon dioxide. It also showed catalytic capability. A 2 mol % portion of 2 catalyzed the hydroboration of carbon dioxide (CO2) with pinacolborane (HBpin) in deuterated benzene (C6D6) at 110 °C (conversion >99%), which afforded the methoxyborane [pinBOMe] (yield 97.8%, TOF 33.3 h-1) and the bis(boryl) oxide [(pinB)2O]. In addition, 5 mol % of 2 catalyzed the N-formylation of secondary and primary amines by carbon dioxide and pinacolborane to yield the N-formamides (average yield 91.6%, TOF 25.9 h-1). Moreover, 2 showed chemoselectivity toward catalytic hydroboration of carbonyl compounds. In mechanistic studies, the B= B double bond in compound 2 activated the substrates, the intermediates of which then underwent hydroboration with pinacolborane to yield the products and regenerate catalyst 2.
Transforming atmospheric CO2 into alternative fuels: A metal-free approach under ambient conditions
Chandra Sau, Samaresh,Bhattacharjee, Rameswar,Hota, Pradip Kumar,Vardhanapu, Pavan K.,Vijaykumar, Gonela,Govindarajan,Datta, Ayan,Mandal, Swadhin K.
, p. 1879 - 1884 (2019/02/12)
This work demonstrates the first-ever completely metal-free approach to the capture of CO2 from air followed by reduction to methoxyborane (which produces methanol on hydrolysis) or sodium formate (which produces formic acid on hydrolysis) under ambient conditions. This was accomplished using an abnormal N-heterocyclic carbene (aNHC)-borane adduct. The intermediate involved in CO2 capture (aNHC-H, HCOO, B(OH)3) was structurally characterized by single-crystal X-ray diffraction. Interestingly, the captured CO2 can be released by heating the intermediate, or by passing this compound through an ion-exchange resin. The capture of CO2 from air can even proceed in the solid state via the formation of a bicarbonate complex (aNHC-H, HCO3, B(OH)3), which was also structurally characterized. A detailed mechanism for this process is proposed based on tandem density functional theory calculations and experiments.