Lewis Acid Catalysis with Cationic Dinuclear Gold(II,II) and Gold(III,III) Phosphorus Ylide Complexes
作者:Benjamin R. Reiner、Mark W. Bezpalko、Bruce M. Foxman、Casey R. Wade
DOI:10.1021/acs.organomet.6b00403
日期:2016.9.12
The.dinuclear gold(II,II) and gold(III,III) complexes [Au-2(mu-PY)(2)(MeCN)(2)]OTf2 (2-OTf2) and [Au-2(mu-PY)(2)(mu-CH2)(MeCN)(2)]OTf2 (3-OTf2) (PY = [(CH2)(2)PPh2](-)) have been synthesized and evaluated as Lewis acid catalysts for Mukaiyama addition and alkyne hydroamination reactions. 2-OTf2 and 3-OTf2 provide similar or improved catalytic activity for these reactions compared to the commonly used gold(I) Lewis acids Ph3PAuOTf and IPrAuOTf. The versatile Lewis acidity of 2-OTf2 was further demonstrated by its superior performance in a cascade reaction involving intramolecular hydroamination followed by intermolecular conjugate addition to generate a 2,3-substituted indole.
Versatile One-Step One-Pot Direct Aldol Condensation Promoted by MgI2
作者:Han-Xun Wei、Kunyu Li、Qian Zhang、Richard L. Jasoni、Jiali Hu、Paul W. Paré
DOI:10.1002/hlca.200490211
日期:2004.9
A true one-stepone-pot aldol-reaction procedure has been developed for the synthesis of β-hydroxy ketones and esters. The reaction can be run at room temperature by simply mixing four components in CH2Cl2, with medium-to-high yields of aldol products obtained after regular workup. Mechanistically, the process probably proceeds via Mg-enolate formation of the ketone or ester component, followed by