Highly Efficient, Facile, Room Temperature Intermolecular [5 + 2] Cycloadditions Catalyzed by Cationic Rhodium(I): One Step to Cycloheptenes and Their Libraries
作者:Paul A. Wender、Lauren E. Sirois、René T. Stemmler、Travis J. Williams
DOI:10.1021/ol100337m
日期:2010.4.2
A cationic rhodium(I) complex-[(C(10)H(8))Rh(cod)](+) SbF(6)(-)-Catalyzes the remarkably efficient intermolecular [5 + 2] cycloaddition of vinylcyclopropanes (VCPs) and various alkynes, providing cycloheptene cycloadducts in excellent yields in minutes at room temperature. The efficacy and selectivity of this catalyst are also shown in a novel diversification strategy, affording a cycloadduct library in one step from nine commercially available components.
Iridium Catalyzed Carbocyclizations: Efficient (5+2) Cycloadditions of Vinylcyclopropanes and Alkynes
作者:Michaela-Christina Melcher、Henrik von Wachenfeldt、Anders Sundin、Daniel Strand
DOI:10.1002/chem.201405729
日期:2015.1.7
Third‐row transition metal catalysts remain a largely untapped resource in cycloaddition reactions for the formation of medium‐sized rings. Herein, we report the first examples of iridium‐catalyzed inter‐ and intramolecular vinylcyclopropane (VCP)–alkyne (5+2) cycloadditions. DFT modeling suggests that catalysis by iridium(I) proceeds through a mechanism similar to that previously reported for rhodium(I)‐catalyzed