Regioselective Prenylation of Phenols by Palladium Catalyst: Syntheses of Prenylphenols and Chromans
摘要:
The palladium-catalyzed coupling reaction of iodophenols (1) with 2-methyl-3-butyn-2-ol gave alkynylphenols (2). Catalytic hydrogenation of 2 over Raney nickel and the subsequent dehydration of the resultant alkylphenols (3) gave regioselectively the desired prenylphenols (4). Dehydration of alkylphenols (3f-h) gave chromans (7).
Calcium-Catalyzed Friedel-Crafts Alkylation at Room Temperature
作者:Meike Niggemann、Matthias J. Meel
DOI:10.1002/anie.200907227
日期:2010.5.10
A novel calcium catalyst was found to efficiently functionalize electron‐rich arenes with secondary and tertiary benzylic, propargylic, and allylic alcohols under very mild reaction conditions. The new catalyst system significantly enlarges the scope of the reaction, which was previously limited except for the few examples with secondary benzylicalcohols.
Gold(I)-catalyzed intermolecular hydroarylation of allenes with nucleophilic arenes: scope and limitations
作者:Michael A. Tarselli、Ann Liu、Michel R. Gagné
DOI:10.1016/j.tet.2008.10.110
日期:2009.2
The addition of nucleophilic methoxyarenes to allenes proceeds at room temperature in dichloromethane with a catalytic amount of phosphite-gold(I) precatalyst and silver additive. The addition is regioselective for the allene terminus, and generates E-allylation products without the need for prefunctionalization of the synthons as organometallics or allyl bromides. Coordinating heteroaromatics and