2890-88-2Relevant academic research and scientific papers
Reductive dechlorination of BCl3 for efficient ammonia borane regeneration
Tan, Yingbin,Zhang, Lijun,Chen, Xiaowei,Yu, Xuebin
, p. 753 - 757 (2015/02/19)
This paper reports a complete ammonia borane (AB) regeneration process in which Bu3SnH was utilized as a reductant for the reductive dechlorination of BCl3, and Et2PhN was selected as a 'helper ligand' to generate Et2PhN·BH3, which gives rise to a high yield of AB by a base-exchange reaction at ambient temperature.
Hydrodechlorination of Et3NBCl3 catalyzed by amorphous nickel boride - A mechanistic approach
Reller, Christian,Mertens, Florian O.R.L.
, p. 450 - 459 (2014/02/14)
The catalytic hydrodechlorination of BCl3 with molecular hydrogen in the presence of tertiary amines is a viable strategy for the energy-efficient generation of valuable B-H bonds. A mechanistic study based on experiments with isolated intermediates and deuterium labeling experiments is presented. The occurrence of the rate-limiting reverse reaction from the insoluble Et3NHCl adduct was identified as a major cause of low Et3NBH3 yields. In addition, amines with NCH2 units, which also serve in the corresponding cases as solvents, have a strong influence on the reaction kinetics; they are directly involved in the hydrogen transfer at elevated temperatures and assume the role of a cocatalyst. A catalytic cycle for the reaction on a nickel boride catalyst is proposed. Copyright
Hydrodechlorination of Et3NBCl3 catalyzed by amorphous nickel boride - A mechanistic approach
Reller, Christian,Mertens, Florian O. R. L.
, p. 450 - 459 (2015/04/27)
The catalytic hydrodechlorination of BCl3 with molecular hydrogen in the presence of tertiary amines is a viable strategy for the energy-efficient generation of valuable B-H bonds. A mechanistic study based on experiments with isolated intermediates and deuterium labeling experiments is presented. The occurrence of the rate-limiting reverse reaction from the insoluble Et3NHCl adduct was identified as a major cause of low Et3NBH3 yields. In addition, amines with NCH2 units, which also serve in the corresponding cases as solvents, have a strong influence on the reaction kinetics; they are directly involved in the hydrogen transfer at elevated temperatures and assume the role of a cocatalyst. A catalytic cycle for the reaction on a nickel boride catalyst is proposed. The mechanistic aspects of the generation of borane species from BCl3 by catalytic hydrodechlorination with molecular hydrogen in the presence of tertiary amines are investigated. The NCH2 units of the amines are particularly important to the overall reaction kinetics and these units are assigned the role of cocatalyst. Equilibrium investigations guide the way for the improvement of the synthesis.
A self-contained regeneration scheme for spent ammonia borane based on the catalytic hydrodechlorination of BCl3
Reller, Christian,Mertens, Florian O.R.L.
supporting information, p. 11731 - 11735 (2013/01/15)
Recycling: A self-contained procedure for the recycling of BNH-waste, based on the three major steps: polymer break-up, amine supported catalytic hydrodehalogenation of boron halogens, and the base exchange in borane amine adducts, is developed (see picture). Beyond the original task of recycling spent ammonia borane, the process provides a new means to produce borohydride species efficiently, by the direct use of molecular hydrogen. Copyright
Mixed Boron Trihalide Adducts of Amines: A Multinuclear Nuclear Magnetic Resonance Study
Fox, Arnold,Hartman, Stephen J.,Humphries, Robyn E.
, p. 1275 - 1284 (2007/10/02)
The (19)F chemical shifts of mixed boron trihalide adducts of tertiary amines have a marked dependence on the steric effects of amine substituents, as estimated from the 'cone angle' of the amines.Base strength of the amine has little effect on adduct (19)F shifts, but does have a pronounced effect on the rate of halogen redistribution.The (11)B and (13)Cchemical shifts and (11)B-(19)F coupling constants of the adducts are discussed.Amines NRR'R'' become chiral when complexed to Lewis acids, since complexation stops the rapid inversion process.Because of this the fluorines in R''R'RN*BF2X (X=Cl, Br, or I) adducts are diastereotopic and magnetically non-equivalent, differing in chemical shift by up to 2 p.p.m.The four-adduct system of benzyl(ethyl)methylamine with BF(n)I(3-n)(n=0-3) gives rise to the cation B(PhCH2NMeEt)2F2(1+) which, because of the chirality of the co-ordinated amines, exists in meso and optically active forms distinguishable by (19)F n.m.r. spectroscopy.
Trends in the proton nuclear magnetic resonance spectra of some amine-haloboranes. Steric effects
Myers,Ryschkewitsch,Mathur,King
, p. 2874 - 2881 (2007/12/18)
Borane adducts of trimethylamine and diethylamine were halogenated using free halogens or hydrogen halides, and the proton NMR spectra of these amine-haloborane adducts were obtained. The resonances of these adducts showed a shift to lower field with increased size of halogen or with increased number of halogens on boron. This shift to lower field had been previously attributed to inductive effects, but in this work it was shown that the shift to lower field was due to steric interaction between halogens on boron and alkyl groups on nitrogen. Proton NMR spectra for diethylamine-haloboranes were complex and showed patterns attributable to nonequivalent methylene protons. Computer analyses of the spectra allowed assignments consistent with preferred rotational configurations.
