Tandem Catalysis: Generating Multiple Contiguous Carbon−Carbon Bonds through a Ruthenium-Catalyzed Ring-Closing Metathesis/Kharasch Addition
作者:Benjamin A. Seigal、Cristina Fajardo、Marc L. Snapper
DOI:10.1021/ja055806j
日期:2005.11.23
0], and [5.3.0] ring systems in one step from the appropriately functionalized acyclic precursors. For substrates where the intramolecular Kharasch addition fails, an intermolecularKharasch addition is possible. By combining the intra- and intermolecularKharasch additions with RCM, three new contiguous carbon-carbon bonds with multiple stereocenters can be generated by the ruthenium catalyst in a controlled
monitored by (1)H and (3)(1)P NMR spectroscopies in order to understand the intimate details of the catalytic cycles. Polyhalogenated substrates and the ethylene released upon metathesis induced the clean transformation of catalystprecursor 1 into the Ru(II)-Ru(III) mixed-valence compound [(p-cymene)Ru(mu-Cl)(3)RuCl(2)(PCy(3))], which was found to be an efficient promoter for atomtransferradical reactions