Readily available from esters or ketones, cyclopropanols are inclined to undergo diverse ring-opening transformations. Their one-electron oxidation is a conventional way to β-carbonyl radicals. However, despite this fact, their application as a coupling partner in dual photoredox and nickel-catalyzed reactions with organic halides remains underdeveloped. Here, we report that the Ti(OiPr)4 additive
环丙醇很容易从酯或酮中获得,倾向于进行各种开环转化。它们的单电子氧化是β-羰基自由基的常规方式。然而,尽管如此,它们作为偶联伙伴在与有机卤化物的双重光氧化还原和镍催化反应中的应用仍然不成熟。在这里,我们报告了 Ti(O i Pr) 4添加剂使这种难以捉摸的与芳基溴和烯基溴的交叉偶联成为可能,从而产生 β 取代的酮。
Boron‐Catalyzed C−C Functionalization of Allyl Alcohols
talyzed C−C bond functionalization of arylallyl alcohols using donor‐acceptor carbenes is presented. The allylic hydroxyl group is found to assist the product formation by neighboring group participation providing a clue towards mechanistic understanding. This method can also be employed to effect homologation of allylalcohols to homoallyl alcohols. Overall, this metal‐free transformation presents
Catalyst-free, visible-light-promoted S–H insertion reaction between thiols and α-diazoesters
作者:Jingya Yang、Ganggang Wang、Shuwen Chen、Ben Ma、Hongyan Zhou、Menghui Song、Cai Liu、Congde Huo
DOI:10.1039/d0ob02006k
日期:——
A visible-light-promoted S–H insertion reaction betweenthiols and α-diazoesters was developed. The reaction proceeded smoothly at room temperature with a broad substrate scope, affording various thioethers in moderate to excellent yields. The catalyst- and additive-free nature, sustainable energy source and mild reaction conditions make this strategy more eco-friendly.
Three-Component Ring-Opening Reactions of Cyclic Ethers, α-Diazo Esters, and Weak Nucleophiles under Metal-Free Conditions
作者:Lin Lu、Chuwei Chen、Huanfeng Jiang、Biaolin Yin
DOI:10.1021/acs.joc.8b02091
日期:2018.12.7
A protocol for three-component reactions of cyclic ethers, α-diazo esters, and weak nitrogen, oxygen, carbon, and sulfur nucleophiles (pKa = 2.2–14.8) to afford a variety of structurally complex α-oxyalkylated esters is reported. These reactions involve intermolecular activation of the cyclic ether (present in excess) by the α-diazo ester to form an oxonium ylide under metal-free conditions, followed
据报道,存在一种用于环醚,α-重氮酯与弱氮,氧,碳和硫亲核试剂(p K a = 2.2–14.8)的三组分反应的协议,该反应可提供多种结构复杂的α-氧基烷基化酯。这些反应包括在无金属条件下,α-重氮酯对环状醚(过量存在)进行分子间活化,形成叶立德叶立酮,然后由亲核试剂开环。
A Stereodivergent Approach to the Synthesis of
<i>gem</i>
‐Diborylcyclopropanes
A designed strategy for a highly efficient protocol for the diastereodivergent construction of gem-dibroylcyclopropanes has been established. This was accomplished via the Pd(OAc)2-catalyzed cyclopropanation reaction of the gem-diborylalkene “carbenophile-reactive” groups with different α-diazoarylacetates and α-diazoaryl-CF3.