نتایج جستجو برای: regio and chemoselective
تعداد نتایج: 16827812 فیلتر نتایج به سال:
A sequential photocatalytic strategy is developed via the merger of Cu(II)/Cu(I)-catalytic cycles for oxoallylation vinyl arenes α-haloketones. The initial Cu(II)-photocatalyzed oxohalogenation exploits ligand-to-metal charge transfer (LMCT) to generate halide radicals from acyl halides utilizing air as a terminal oxidant and can be employed late-stage modification pharmaceuticals agrochemicals...
Metalloporphirins; Cu(TPP), Mn(TPP)Cl, CO(TPP), Fe(TPP)Cl, zn(TPP) and Mn(OBP)Cl catalyze region and chemoselective silylation of hydroxyl groups with HMDS. Fe(TPP)Cl is the most effective catalyst and silylation occurs immediately in its presence at room temperature.
An overview of the synthesis and applications of chiral 2,3-epoxy alcohols containing unsaturated chains is presented. One of the fundamental synthetic routes to these compounds is Sharpless asymmetric epoxidation, which is reliable, highly chemoselective and enables easy prediction of the product enantioselectivity. Thus, unsaturated epoxy alcohols are readily obtained by selective oxidation o...
The regio- and chemoselective oxidation of unprotected vicinal polyols with [(neocuproine)Pd(OAc)]2(OTf)2 (1) (neocuproine = 2,9-dimethyl-1,10-phenanthroline) occurs readily under mild reaction conditions to generate α-hydroxy ketones. The oxidation of vicinal diols is both faster and more selective than the oxidation of primary and secondary alcohols; vicinal 1,2-diols are oxidized selectively...
The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic process...
Silacyclopropanes reacted with carbonyl compounds under mild conditions (10 mol % metal salt, e22 °C) in a stereospecific and highly stereo-, regio-, and chemoselective fashion. In most cases, CuI or CuBr2 were the optimal catalysts although ZnBr2 worked comparably well in a few examples. Insertion occurred with retention of configuration and, in the case of enals and formamides, with high dias...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید