Free-Radical Bromotrifluoromethylation of Olefin via Single-Electron Oxidation of NaSO<sub>2</sub>CF<sub>3</sub> by NaBrO<sub>3</sub>
作者:Zhong-Quan Liu、Dong Liu
DOI:10.1021/acs.joc.6b02812
日期:2017.2.3
A free-radical bromotrifluoromethylation of olefin by using NaSO2CF3 and NaBrO3 has been achieved. Sodium bromate acts not only as a single-electron oxidant but also as a bromine source. A radical-clock experiment and electron-spin-resonance detection support a radical process.
Regio‐ and Stereoselective Chan‐Lam‐Evans Enol Esterification of Carboxylic Acids with Alkenylboroxines
作者:Luuk Steemers、Linda Wijsman、Jan H. van Maarseveen
DOI:10.1002/adsc.201800914
日期:2018.11.5
Efficient and scalable Cu(II)‐mediated enol esterification methodology of carboxylicacids from alkenyl boroxines and boronic acids is presented. The reaction shows a wide scope in aliphatic and aromatic carboxylicacids in combination with several alkenyl boroxines. In the case of 2‐substituted alkenyl boroxines the double bond configuration was fully retained in the enol ester product. Also N‐hydroxyimides
Dinuclear Zinc-Catalyzed Asymmetric Desymmetrization of Acyclic 2-Substituted-1,3-Propanediols: A Powerful Entry into Chiral Building Blocks
作者:Barry M. Trost、Sushant Malhotra、Takashi Mino、Naomi S. Rajapaksa
DOI:10.1002/chem.200800623
日期:2008.8.28
The asymmetric acylation of meso-2-substituted-1,3-propanediols by using an amphoteric chiraldinuclear zinc catalyst is described. It is has been demonstrated that both 2-alkyl- and 2-aryl-1,3-propanediols can be desymmetrized in high yields and enantioselectivities by using the same family of ligands. Given that both antipodes of the chiral catalyst are available, both enantiomers of the desymmetrized
The present invention relates to a process for preparing vinyl carboxylates, wherein a carboxylic acid is reacted with an alkyne compound in the presence of a catalyst which is selected from carbonyl complexes, halides and oxides of rhenium, of manganese, of tungsten, of molybdenum, of chromium and of iron and rhenium metal at a temperature of ≦300° C.
The process gives the desired vinyl esters with high yield.
In this paper, the copper(II)-catalyzed esterification reaction of arenecarboxylic acids with aryl- or vinyl-substituted trimethoxysilanes is described. A series of aryltrimethoxysilanes and arenecarboxylic acids worked well under this procedure, affording aryl benzoate derivatives in moderate to good yields. Notably, trimethoxy(vinyl)silanes also worked well under this procedure giving a facile and versatile method to access vinyl benzoate derivatives.