Nickel catalyzed [3+2] cycloadditionreactions of bis(methylenecyclopropane) with cyclic and acyclic dienophiles have been explored. The reactions resulted in the formation of functionalized cyclopentanes in good yields. The reactions were also explored under microwave irradiation for the first time to yield [3+2] cycloadducts in short reaction time and high yields.
Nucleophilic substitutions of 1-alkenylcyclopropyl esters and 1-alkynylcyclopropyl chlorides catalyzed by palladium(0)
作者:Andreas Stolle、Jean Ollivier、Pier Paolo Piras、Jacques Salaun、Armin De Meijere
DOI:10.1021/ja00037a006
日期:1992.5
dimethylallyl acetates 19 and 22, respectively. Use of chiral phosphines as ligands in the palladium catalyst can provide optically active methylenecyclopropane derivatives. With phenyl-, methyl-, and even n-butylzinc chloride as nucleophiles, the reaction apparently proceeds with initial transfer of the organic residue to palladium, followed by reductive elimination entailing tertiary substitution on the cyclopropane
Rhodium-catalysed chemo- and regio-selective [3 + 2+2] cycloadditions of bis(methylenecyclopropanes) and alkynes: Synthesis of spirocyclic 5–7 condensed cycloheptenes
Abstract Rhodium-catalyzed intermolecular [3 + 2+2] cycloaddition reactions of bis(methylenecyclopropanes) with different alkynes are described. The rhodium-catalyzed [3 + 2+2] cycloadditions resulted in the formation of functionalized 5–7–3 spirocyclic carbocycles in moderate yields with excellent regio- and chemo-selectivity. GRAPHICAL ABSTRACT
Nickel(0)-Catalyzed [3+2]-Cycloadditions of Bis(alkylidenecyclopropanes) with Diazenes: A Facile Synthesis of Functionalized Pyrazolidine-1,2-dicarboxylates
A nickel(0)-catalyzed intermolecular [3+2] cycloaddition of bis(alkylidenecyclopropanes) with diazenes such as diethyl or diisopropyl azodicarboxylate gave pyrazolidine-1,2-dicarboxylates in moderate to good yields (61–72%).