An efficient one-potmethod for the regioselective bromination of allylicalcoholderivatives (two-step reaction sequence) followed by Sonogashira, Negishi, or Suzuki–Miyaura coupling reactions in the same reaction vessel (three-step reaction sequence) has been developed. The key reaction in these one-pot systems is the regioselective DBU-promoted trans HBr elimination of vicinal dibromides bearing
A Pd(II)/sulfoxide-catalyzed sequential allylic C-H oxidation/vinylic C-H arylation of alpha-olefins to furnish E-arylated allylic esters in high regio- and E:Z selectivities (>20:1) is reported. The broad scope of this method with respect to the alpha-olefin, carboxylic acid, and aryl boronic acid enables the rapid assembly of densely functionalized fragments for complex molecule synthesis from cheap, abundant hydrocarbon starting materials. The Pd(II)/sulfoxide-catalyzed vinylic C-H arylation of electronically unbiased olefins with aryl boronic acids proceeds under oxidative, acidic conditions and mild temperatures (room temperature to 45 degrees C).
Ceric(IV) ammonium nitrate in the selective conversion of hydrazides to esters
作者:Bogdan Štefane、Marijan Kočevar、Slovenko Polanc
DOI:10.1016/s0040-4039(99)00764-9
日期:1999.6
Hydrazides were treated with ceric(IV) ammonium nitrate (CAN) in the presence of the appropriate alcohol as a nucleophile to afford esters in good yields. Reactions took place exclusively at the hydrazino moiety even when other sensitive groups were present in either of the partners. (C) 1999 Elsevier Science Ltd, All rights reserved.
Novel One-Pot Method for Chemoselective Bromination and Sequential Sonogashira Coupling
作者:Noriki Kutsumura、Kentaro Niwa、Takao Saito
DOI:10.1021/ol101110v
日期:2010.8.6
An efficient one-pot method for bromination-elimination of allyl alcohol derivatives and sequential Sonogashira coupling has been developed. A highlight of the method is chemoselective DBU-promoted elimination of vicinal dibromoalkanes having an adjacent O-functional group.
Burton, Journal of the Chemical Society, 1929, p. 457