Visible-Light-Promoted Redox-Neutral Cyclopropanation Reactions of α-Substituted Vinylphosphonates and Other Michael Acceptors with Chloromethyl Silicate as Methylene Transfer Reagent
with chloromethyl silicate as a methylene transfer reagent has been accomplished via visible‐light‐mediated redox‐neutral catalysis. This method features broad functional group tolerance and mild conditions. In addition to α‐substituted vinylphosphonates, a range of Michael acceptors including α,β‐unsaturated acrylate, ketone, amide and sulfone are suitable substrates for this photocatalytic cyclopropanation
Reductive Coupling of Acrylates with Ketones and Ketimines by a Nickel-Catalyzed Transfer-Hydrogenative Strategy
作者:Craig S. Buxton、David C. Blakemore、John F. Bower
DOI:10.1002/anie.201707531
日期:2017.10.23
next cycle where it serves as the reductant for C-C bond formation. This strategy represents a conceptually unique approach to transfer-hydrogenative C-C bond formation, thus providing examples of reductive heterocyclizations where hydrogen embedded within an alcohol leaving group facilitates turnover.
丙烯酸苄酯与活化的酮和亚胺在镍催化下偶联,分别生成γ-丁内酯和内酰胺。内酯化/内酰胺化过程中释放的苯甲醇副产物被传递到下一个循环,在其中充当 CC 键形成的还原剂。该策略代表了一种概念上独特的转移氢化CC键形成方法,从而提供了还原性杂环化的例子,其中氢嵌入醇离去基团中促进周转。
Visible-light-promoted photocatalyst- and additive-free intermolecular trifluoromethyl-thio(seleno)cyanation of alkenes
Photocatalyst- and additive-free trifluoromethyl-thio(seleno)cyanation of alkenes using visible light as the sole promoter is reported.
无需光催化剂和添加剂,利用可见光作为唯一的促进剂,报道了烯烃的三氟甲硫(硒)氰化反应。
Rhodium-Catalyzed Hydrocarboxylation of Olefins with Carbon Dioxide
作者:Shingo Kawashima、Kohsuke Aikawa、Koichi Mikami
DOI:10.1002/ejoc.201600338
日期:2016.7
excellent yields. In this catalytic process with carbon dioxide, intervention of the RhI–H species, which could be generated from the RhI catalyst and diethylzinc, was clarified. Significantly, the catalyticasymmetric hydrocarboxylation of α,β-unsaturated esters with carbon dioxide was also performed by employing a cationic rhodium complex possessing (S)-(–)-4,4′-bi-1,3-benzodioxole-5,5′-diylbis(diphenylphosphine)
α-Aminoxy-Acid-Auxiliary-Enabled Intermolecular Radical γ-C(sp<sup>3</sup>
)−H Functionalization of Ketones
作者:Heng Jiang、Armido Studer
DOI:10.1002/anie.201712066
日期:2018.2.5
site‐specific intermolecular γ‐C(sp3)−H functionalization of ketones has been developed using an α‐aminoxy acid auxiliary applying photoredox catalysis. Regioselective activation of an inert C−H bond is achieved by 1,5‐hydrogen atom abstraction by an oxidatively generated iminyl radical. Tertiary and secondary C‐radicals thus formed at the γ‐position of the imine functionality undergo radicalconjugate addition