An Improved Method for the Protection of Carboxylic Acids as 1,1-Dimethylallyl Esters
作者:Minoo Sedighi、Selçuk Çalimsiz、Mark A. Lipton
DOI:10.1021/jo061207z
日期:2006.12.1
1,1-Dimethylallyl (DMA) esters of various N-protected amino acids have been synthesized using prenyldimethylsulfonium tetrafluroborate, a reagent that can be readily made and stored, in conjunction with catalytic CuBr. These reactions were complete within several hours and afforded DMA esters in high yields. As has been previously shown in our group, DMA esters represent a palladium-labile proctecting
A Convenient, General Synthesis of 1,1-Dimethylallyl Esters as Protecting Groups for Carboxylic Acids
作者:Minoo Sedighi、Mark A. Lipton
DOI:10.1021/ol0476117
日期:2005.4.14
1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl, and Fmoc protectinggroups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection