We report the visible light photocatalytic cleavage of trityl thioethers or ethers under pH-neutral conditions. The method results in the formation of the respective symmetrical disulfides and alcohols in moderate to excellent yield. The protocol only requires the addition of a suitable photocatalyst and light rendering it orthogonal to several functionalities, including acid labile protective groups
作者:Christopher W. West、M. Angels Estiarte、Daniel H. Rich
DOI:10.1021/ol015678d
日期:2001.4.1
Cysteine sulfhydryl protection with either the Fmoc or the Fm group was accomplished in one step and in high yield using commercially available FmocCI or FmocOSu, respectively, Mechanisms for the Fmoc to Fm transformations are discussed. Additionally, Fmoc-Cys(Fmoc)OH (7) was synthesized and used in amide bond forming reactions. The S-Fmoc group is cleaved selectively from peptides containing the N-Fmoc group.
The allyloxycarbonylaminomethyl group: a new allytic protection for the thiol group of cysteine
S-Allocam derivatives of thiols in general and of cysteine in particular are selectively and readily deprotected through palladium catalyzed hydrostanoolysis. They are perfectly stable in the basic conditions of Fmoc-removal. but only marginally stable in the acidic conditions of t-Bu, Boc removal.