Metal‐bound water molecules have recently been recognized as a new facet of soft Lewis acid catalysis. Herein, a chiral palladium aqua complex was constructed that enables carbon–hydrogen bonds of indoles to be functionalized efficiently. We embraced a chiral 2,2′‐bipyridine as both ligand and hydrogen‐bond donor to configure a robust, yet highly Lewis acidic, chiral aqua complex in water. Whereas the
Lithium Cobalt-Bis-Dicarbollide: A Novel Lewis Acid Catalyst for the Conjugate Addition of Silyl Ketene Acetals to Hindered .alpha.,.beta.-Unsaturated Carbonyl Compounds
作者:William J. DuBay、Paul A. Grieco、Lee J. Todd
DOI:10.1021/jo00102a009
日期:1994.11
The novel Lewis acid, lithium cobalt-bis-dicarbollide (1), in which the lithium ion is weakly coordinated to the Co(B9C2H11)(2)(1-)anion, is an effective, soluble catalyst for Mukaiyama-Michael reactions.