Reactivity of bismuth(III) halides towards alcohols. A tentative to mechanistic investigation
作者:El Mehdi Keramane、Bernard Boyer、Jean-Pierre Roque
DOI:10.1016/s0040-4020(01)00013-8
日期:2001.3
bismuth(III) halides (BiX3; X=Cl, Br and I) towards a series of alcohols has been investigated. Three different reactions have been studied, namely: halogenation, dehydration and etherification. The behaviour of these bismuth derivatives was found to depend on the nature of the halide bonded to the bismuth atom. Their reactivities can be interpreted on the basis of the Hard and Soft Acids and Bases
研究了卤化铋(III)(BiX 3; X = Cl,Br和I)对一系列醇的反应性。已经研究了三种不同的反应,即:卤化,脱水和醚化。发现这些铋衍生物的行为取决于结合到铋原子上的卤化物的性质。它们的反应性可以根据硬酸和软酸和碱(HSAB)原理进行解释。提出了一种机制,该机制涉及形成醇与Bi(III)的复合物。
Enantioselectivity of Haloalkane Dehalogenases and its Modulation by Surface Loop Engineering
作者:Zbynek Prokop、Yukari Sato、Jan Brezovsky、Tomas Mozga、Radka Chaloupkova、Tana Koudelakova、Petr Jerabek、Veronika Stepankova、Ryo Natsume、Jan G. E. van Leeuwen、Dick B. Janssen、Jan Florian、Yuji Nagata、Toshiya Senda、Jiri Damborsky
DOI:10.1002/anie.201001753
日期:2010.8.16
In the loop: Engineering of the surfaceloop in haloalkanedehalogenases affects their enantiodiscrimination behavior. The temperature dependence of the enantioselectivity (lnE versus 1/T) of β‐bromoalkanes by haloalkanedehalogenases is reversed (red data points) by deletion of the surfaceloop; the selectivity switches back when an additional single‐point mutation is made. This behavior is not observed
Stereochemical dissection of a carbene fragmentation reaction
作者:Robert A. Moss、Pawel Balcerzak
DOI:10.1021/ja00050a018
日期:1992.11
The fragmentation of (S)-3-(2-butoxy)-3-chlorodiazirinc (9) in acetonitrile proceeds via N 2 loss to (S)-2-butoxychlorocarbene (10) and thence via CO scission to a 2-butyl cation/chloride anion pair (11) that collapses to (S)-2-chlorobutane (12) with ∼56% net retention. In 1-butanol, ion pair 11 affords 55% chloride 12 by ion pair return with 82% net retention and 45% of (R)-2-butyl 1-butyl ether (13)
The alkylation of benzene with (+)-2-chlorobutane (1) by Lewis acid catalyst gave stereospecifically (−)-2-phenylbutane (2) with inversion of configuration at low temperature for short reaction times. A lowering of the stereospecificity of the reaction was found to be partly due to the racemization of (+)-1 and (−)-2.