Reactions of bromotrifluoromethane with acid derivatives in the presence of zinc
作者:C. Francèse、M. Tordeux、C. Wakselman
DOI:10.1016/0040-4039(88)85326-7
日期:1988.1
Reaction of zinc with bromotrifluoromethane in pyridine gives poorly reactive trifluoromethyl zinc derivatives in the presence of ethyl benzoate whereas the Barbier condensation occurs with activated esters, like ethyl trifluoroacetate or ethyloxalate, and cyclic anhydrides.
A New Class of Urea-Substituted Cinchona Alkaloids Promote Highly Enantioselective Nitroaldol reactions of Trifluoromethylketones
作者:Carole Palacio、Stephen J. Connon
DOI:10.1021/ol103089j
日期:2011.3.18
The first class of bifunctional cinchona-alkaloid catalysts incorporating a urea moiety at C-5′ has been developed. These materials catalyze the efficient and highly enantioselective 1,2-addition of nitromethane to trifluoromethylketones to form synthetically pliable products incorporating a quaternary stereocenter. Excellent product yields and levels of enantiomeric excess are possible, and the optimum
Most of NdBaCuO synthesis were realized under oxygen controlled melt growth (OCMG) which allows to avoid the solid solution formation. However, for industrial applications air synthesis is preferable due to its simplicity and its cost. In this work, different seeds and thermal cycles have been investigated in order to optimize the nucleation conditions for the obtention of a single domain. Several criteria have been defined for the choice of the seed. The solid solution Nd1+xBa2−xCu3Oy formed in these air synthesised samples appears in the range of x = 0.10 to 0.15, corresponding to between 60 K and 80 K. The nominal composition and the synthesis conditions (substrate, thermal treatments.) have to be accurately defined in order to avoid neodymium-rich solid solution formation.
Application of the modified Mosher method using high-field FT 1H NMR to the 2-methoxy-2-phenyl-2-trifluoromethyl acetic acid (MTPA) derivatives of fluorinated secondaryalcohols indicates that this method may be generally used to determine the absoluteconfigurations of these materials.
使用高场FT 1 H NMR的改良Mosher方法在氟化仲醇的2-甲氧基-2-苯基-2-三氟甲基乙酸(MTPA)衍生物上的应用表明,该方法通常可用于确定绝对构型这些材料。
A General and Highly Selective Method for the Asymmetric Synthesis of Trifluoromethyl-Substituted<i>α</i>- and<i>β</i>-Aminophosphonates
作者:Lijing Wang、Qilong Shen、Long Lu
DOI:10.1002/cjoc.201300344
日期:2013.7
A highly selective method for the asymmetric formation of trifluoromethyl‐substitutedα‐ and β‐aminophosphonates was described. The reaction proceeded with high yields and good to excellent diastereoselectivity. The product can be easily converted into corresponding trifluoromethyl‐substituted aminophosphoric acids.