The cross-coupling reaction of arylboronicacids (1.3 equivs) with aryl methane-sulfonates was carried out in the presence of a nickel(0) catalyst (3 mol%) and K3PO4·nH2O (3 equivs). The use of toluene as the solvent and the nickel(0)-dppf catalyst prepared from NiCl2(dppf) plus dppf with BuLi were recognized to be the most efficient to achieve both high yields and high selectivity. The reaction can
在镍(0)催化剂(3摩尔%)和K 3 PO 4 ·nH 2 O(3当量)的存在下,进行芳基硼酸(1.3当量)与芳基甲烷磺酸盐的交叉偶联反应。公认使用甲苯作为溶剂以及由NiCl 2(dppf)加dppf与BuLi制备的镍(0)-dppf催化剂是实现高收率和高选择性的最有效方法。该反应可用于各种电子不足和富集的芳基甲磺酸盐,以得到高产率。
Palladium on carbon-diethylamine-mediated hydrodeoxygenation of phenol derivatives under mild conditions
under the Pd/C-catalyzed hydrogenation conditions in the presence of diethylamine and the method could also be applicable to the hydrodeoxygenation of morphine to afford 3-deoxy-7,8-dihydromorphine. Diethylamine is not only a scavenger of the corresponding methanesulfonic acid derivative, which is produced during the reaction progress, but also a strong promoter of the Pd/C-catalyzedreduction of aryl
Visible‐Light‐Mediated Heterocycle Functionalization via Geometrically Interrupted [2+2] Cycloaddition
作者:Mihai V. Popescu、Aroonroj Mekereeya、Juan V. Alegre‐Requena、Robert S. Paton、Martin D. Smith
DOI:10.1002/anie.202009704
日期:2020.12.14
cyclization in the triplet excited state to yield a 1,4‐diradical; intersystem crossing leads preferentially to the closed shell singlet zwitterion. This is geometrically restricted from undergoing recombination to yield a cyclobutane by the planarity of the amide substituent. A prototropic shift leads to the observed bicyclic products in what can be viewed as an interrupted [2+2] cycloaddition.