dihydroazepine rings by a cascadereaction encompassing a rhodium-catalyzed cycloisomerization of 1,5-bisallenes and a [4+2] cycloaddition. This transition metal-catalyzed cascadereaction provides a versatile and step-economical approach to the synthesis of 6,7-membered polyheterocyclic fullerene adducts. Electrochemical characterization of the products obtained ventures their application in organic and perovskite
据报道,一种合成方法通过包括铑催化的 1,5-双丙二烯环异构化和 [4+2] 环加成的级联反应,用二氢氮杂环将C 60和 C 70富勒烯官能化。这种过渡金属催化的级联反应为合成 6,7 元多杂环富勒烯加合物提供了一种通用且步骤经济的方法。获得的产品的电化学表征冒险它们在有机和钙钛矿光伏器件中的应用。
Nickel-catalyzed [2 + 2] cycloaddition reaction using bisallenes
nickel-catalyzed [2 + 2] cycloaddition of bisallenes has been described. Simple bisallenes are employed for the formation of “head to head” cycloadducts in the presence of Ni(0) with xantphos. The dienyl moiety in a product were applicable for various [4 + 2] cycloadditionreactions. Allene-allenamides under Ni-xantphos system gave the tricyclic compounds through sequential [2 + 2]–[4 + 2] cycloaddition reaction
The carbocyanative cyclization of allene–ynes and bis-allenes under nickel catalysis is described. The key steps are the regioselective hydronickelation of allenes and subsequent cyclization via carbometalation. The former step determines the reaction pathway, and the latter controls the stereochemistry of substituted olefins. The products are useful carbo- and heterocycles that include a cyano group
The synthesis of spiro compounds featuring seven- and six-membered rings in the spirobicyclic motif is successfully achieved through a cascade process encompassing a rhodium(I)-catalyzedcycloisomerization followed by a highly selective Diels–Alder homodimerization. The scope of the reaction is analyzed based on a series of synthetic substrates, and control experiments and DFT calculations led us to
germastannylation of bis(allenes) with germylstannanes, catalyzed by palladium complexes, for the construction of cis or trans five-membered cyclic systems has been investigated. We observed that the relative stereochemical arrangements of the reaction products depends on the substituents in the reagents containing Ge−Sn σ-bonds. When the reagent Ph3GeSnBu3 was employed in the Pd0-catalyzed carbocyclization of bis(allenes)