Thermal decomposition of vinylic copper(I) and silver(I) organometallic compounds
作者:George M. Whitesides、Charles P. Casey、Jeanne K. Krieger
DOI:10.1021/ja00735a011
日期:1971.3
s'7-rr During these studies several-qroups have prepared and characterizecl authentic aromatic and vinylic organonretallic compounds of these me[als.'-r'r The thernial stability of this class of compounds , although low conrpared with the stabilities ol nrain group organometallic cotltpounds, appeared tu Lrs to be sullicient to make a derailed investigation ot' the ir thernral decom position a practical
Synthesis of TSF Donors Substituted with the<i>meso</i>-Dimethylethylenedithio Group: Structures and Conducting Properties of (<i>meso</i>-DM-BETS)<sub>2</sub>X (X<sup>−</sup>= PF<sub>6</sub><sup>−</sup>and AsF<sub>6</sub><sup>−</sup>)
analysis of TSF-based donors substituted with the meso-dimethylethylenedithio group (meso-DM-EDT-TSF and meso-DM-BETS) were successfully performed. The donor molecules in (meso-DM-BETS)2X (X– = PF6– and AsF6–) formed a dimerized face-to-face π-stack, and the packing pattern could be classified as β-type. A tight-binding band calculation suggested that the meso-DM-BETS salts have a two-dimensional Fermi
成功地进行了被内消旋-二甲基乙二硫基取代的基于 TSF 的供体的合成和 X 射线结构分析(内消旋-DM-EDT-TSF 和内消旋-DM-BETS)。( meso -DM-BETS) 2 X (X – = PF 6 – and AsF 6 – )中的供体分子形成二聚化的面对面π-堆叠,堆积模式可归类为β型。紧束缚带计算表明,meso -DM-BETS 盐具有宽带宽的二维费米面。两种盐都表现出低至 2.0 K 的金属电导率,σ r.t。= 45–46 厘米–1。
Haloalkane dehalogenase catalysed desymmetrisation and tandem kinetic resolution for the preparation of chiral haloalcohols
作者:Alja Westerbeek、Jan G.E. van Leeuwen、Wiktor Szymański、Ben L. Feringa、Dick B. Janssen
DOI:10.1016/j.tet.2012.06.059
日期:2012.9
Six different bacterial haloalkane dehalogenases were recombinantly produced in Escherichia coli, purified, and used to catalyse the conversion of prochiral short-chain dihaloalkanes and a meso dihaloalkane, yielding enantioenriched haloalcohols. A two-reaction one-enzyme process was established in which the desymmetrisation of a dihaloalkane is followed by kinetic resolution of the chiral haloalcohol that is produced in the first step. In case of 1,3-dibromo-2-methylpropane and 1,3-dibromo-2-phenylpropane, an increase of the enantiomeric excess of the respective haloalcohol was observed in time, leading to ee values of >97%, with analytical yields of 24 and 52%, respectively. The results show that haloalkane dehalogenases can be used for the production of highly enantioenriched haloalcohols and that in some cases product enantiopurity can be improved by allowing a two-step one-enzyme tandem reaction. (C) 2012 Elsevier Ltd. All rights reserved.
Brominative Deoxygenation of some aldehydes and ethers
作者:Ulrich Von Roman、Rudolf Knorr、Claudia Behringer、Jakob Ruhdorfer
DOI:10.1002/prac.19943360313
日期:——
Three aldehydes (4a-c) are transformed into 1,1-dibromides (6a-c) by 2,2,2-tribromo-2,2-dihydro-1,3,2-benzodioxaphosphole (2). This reagent (2) is also very active in the cleavage of ethers, its reactions may show some features of carbonium as well as Of S(N)2 character.