Relevant articles and documents
All total 58 Articles be found
de Moor,J.E.,van der Kelen,G.P.
, p. 235 - 241 (1966)
Burg, A. B.,Schlesinger, H. I.
, p. 4020 - 4025 (1933)
Infrared spectra of B(OMe)3, ClB(OMe)2 and Cl2BOMe species, isolated CH streching frequencies and bond strengths
McKean, D. C.,Coats, A. M.
, p. 409 - 420 (1989)
Infrared spectra in the gas phase are reported over the range 3100-500 cm-1 for species of B(OMe)3, ClB(OMe)2 and Cl2BOMe, with CH3, CD3 and CHD2 substitution.A detailed analysis of νCH and νCD data in all three species of Cl2BOMe yields strong evidence for the presence of three kinds of CH bond, two of them weak and one of them strong.The methyl group is then twisted, probably through 10-20 deg, out of the eclipsed or staggered conformation.The CHD2 spectra of the di and trimethoxy compounds are less susceptible to analysis, but suggest also the presence of two weak and strong bonds, the former increasing in weakness as the number of methoxy groups increases.This is as expected from the increased competition likely between the lone pair electrons for the empty boron orbital.The spectra of the CD3 species permit a clear assignment of νBO, δsCH3, δsCD3 and δasCD3 modes.In Cl(COCH3)2, νsBO lies at 1278 cm-1.
Action of Lewis acids upon base-pentaborane(9) adducts
Burg, Anton B.,Maya, Leon
, p. 942 - 944 (1975)
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, p. 213 - 215 (1953)
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Burg,Mahler
, p. 4242 (1957)
The alcoholysis of carbon monoxide borane
Malone, Leo J.
, p. 1039 - 1040 (1968)
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Study of the reaction between boron trifluoride methanol complex and sodium methoxide
Wuke, Lang,Weijiang, Zhang,Jiao, Xu,Lei, Zhang
, p. 1530 - 1540 (2014)
The reaction between boron trifluoride methanol complex and sodium methoxide in methanol solution was investigated using conductivity as the reaction indicator. The reaction conditions were examined and a mechanism of this reaction was proposed. Moreover, proper reaction conditions were proposed for boric acid preparation using this reaction. 2014
The degradation of biscarborane
Hawthorne,Owen,Wiggins
, p. 1304 - 1306 (1971)
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Brown,Mead
, p. 3614 (1956)
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Wiesboeck, R. A.,Hawthorne, M. F.
, p. 1642 - 1643 (1964)
Reaction of a 14-vertex carborane with nucleophiles: Formation of nido-C2B12, nido-C2B11, and closo-CB11 carborane anions
Zhang, Jian,Zheng, Fangrui,Chan, Hoi-Shan,Xie, Zuowei
, p. 9786 - 9791 (2009)
Nucleophilic reactions of a 14-vertex closo-carborane are reported. 2, 3-(CH2)3-2,3-C2B12H12 (1) reacts with MeOH at 70 °C to give closo-CB11 anions [1,2-(CH2)3CH(OMe)-1-CB11, H10] - ([2a]-), [1,2-(CH2)3CH(OMe)-1- CB11, H10]- ([2b]- ), and [1,2-(CH2)2CH=CH-1-CB11H10] - ([2c]- ). It is suggested that [2c]- is an intermediate for the isomerizatlon from [2a]- to [2b]- . Treatment of 1 with MeOH/Me3N, 'BuOK or LINMe2 affords nido-C2B12 species [8,9-(CH2) 3-μ-11, 12-(Nu)BH-8,9-C2B11H 11]-(Nu = MeO ([3a]-), BuO ([3b]-), and Me2N ([3c]-)). In the presence of acid such as HCl, anions [3]- are converted to 1. However, [3] undergo deboration reaction, in the presence of bases, to generate a nidO-C2B 11 anion [8, 9-(CH2)38,9-C2B 11H12]- ([4]-) that can also be formed directly from the reaction of 1 with excess CsF or piperidine. Mechanistic studies show that [3a]- is the first intermediate in the reaction of 1 with MeOH and [4]- Is unlikely an intermediate.
Garrett, P. M.,Tebbe, F. N.,Hawthorne, M. F.
, p. 5016 - 5017 (1964)
Acetate-catalyzed hydroboration of CO2 for the selective formation of methanol-equivalent products
Dagorne, Samuel,Dos Santos, Jo?o H. Z.,Jacques, Béatrice,López, Carlos Silva,Nieto Faza, Olalla,Schrekker, Henri S.,Sokolovicz, Yuri C. A.,Specklin, David
, p. 2407 - 2414 (2020/05/13)
The present study details the use of the acetate anion, an inexpensive and robust anion, as a CO2 hydroboration catalyst for the selective formation, in most cases, of methanol-equivalent borane products. Thus, upon heating (90 °C, PhBr), tetrabutylammonium, sodium and potassium acetate (1, 2 and 3, respectively) effectively catalyze CO2 hydroboration by pinacolborane (pinB-H) to afford CO2 reduction products HOCOBpin (A), pinBOCH2OBpin (B) and methoxyborane (C). In most cases, high selectivity for product C with higher borane loading and longer reaction time with a TON of up to 970 was observed. The reduction catalysis remains efficient at low catalyst loading (down to 0.1 mol%) and may also be performed under solvent-free conditions using salt 1 as a catalyst, reflecting the excellent robustness and stability of the acetate anion. In control experiments, a 1/1 1/pinB-H mixture was found to react fast with CO2 at room temperature to produce formate species [pinB(O2CH)(OAc)][N(nBu)4] (5) through CO2 insertion into the B-H bond. DFT calculations were also performed to gain insight into the acetate-mediated CO2 hydroboration catalysis, which further supported the crucial role of acetate as a Lewis base in CO2 functionalization catalysis by pinB-H. The DFT-estimated mechanism is in line with experimental data and rationalizes the formation of the most thermodynamically stable reduction product C through acetate catalysis.
A Versatile NHC-Parent Silyliumylidene Cation for Catalytic Chemo- And Regioselective Hydroboration
Leong, Bi-Xiang,Lee, Jiawen,Li, Yan,Yang, Ming-Chung,Siu, Chi-Kit,Su, Ming-Der,So, Cheuk-Wai
supporting information, p. 17629 - 17636 (2019/11/11)
This study describes the first use of a silicon(II) complex, NHC-parent silyliumylidene cation complex [(IMe)2SiH]I (1, IMe =:C{N(Me)C(Me)}2) as a versatile catalyst in organic synthesis. Complex 1 (loading: 10 mol %) was shown to act as an efficient catalyst (reaction time: 0.08 h, yield: 94%, TOF = 113.2 h-1 reaction time: 0.17 h, yield: 98%, TOF = 58.7 h-1) for the selective reduction of CO2 with pinacolborane (HBpin) to form the primarily reduced formoxyborane [pinBOC(-O)H]. The activity is better than the currently available base-metal catalysts used for this reaction. It also catalyzed the chemo- and regioselective hydroboration of carbonyl compounds and pyridine derivatives to form borate esters and N-boryl-1,4-dihydropyridine derivatives with quantitative conversions, respectively. Mechanistic studies show that the silicon(II) center in complex 1 activated the substrates and then mediated the catalytic hydroboration. In addition, complex 1 was slightly converted into the NHC-borylsilyliumylidene complex [(IMe)2SiBpin]I (3) in the catalysis, which was also able to mediate the catalytic hydroboration.