The first fluoroalkylation of amino acids and peptides in water utilizing the novel iodonium salt (CF3SO2)2NI(Ph)CH2CF3

Abstract

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Syntheses and lipophilicity measurement of Nα/N-terminus-1,1-dihydroperfluoroalkylated α-amino acids and small peptides

“…In the early 1980's, Umemoto and Gotoh [24] synthesized perfluoroalkyl and 1,1-dihydroperfluoroalkyl aryliodonium triflates including (2,2,2-trifluoroethyl)phenyl iodonium triflate, which was later prepared using the modified method by Resnati [25] and used for N-trifluoroethylation of amino alcohols under dry conditions. In the late 1990's, DesMarteau and Montanari [19] introduced N,N-bis(trifluoromethylsulfonyl)imide into (2,2,2-trifluoroethyl)phenyliodonium salt to obtain a novel trifluoroethylating agent which has been used to transfer the 2,2,2-trifluoroethyl group to different nucleophiles in aqueous solutions [20][21][22]. Here, the higher homologues of this reagent are prepared and similarly utilized.…”

“…Therefore, CF 3 CH 2 OH (log P 0.41) is more lipophilic than CH 3 CH 2 OH (log P À0.32) [16], though trifluoroethanol (pK a 12.4) [17] is considerably more acidic than ethanol (pK a 15.9) [18]. Based on this rationale, it was expected that the attachment of CF 3 CH 2 -group to the aamino group of amino acids could change both nucleophilicity [19][20][21][22] and lipophilicity of the parent compounds, and possibly, improve their resistance to degradation caused by aminopeptidases.…”

The first example of linear peptides containing a N-trifluoroethylated backbone amide linkage and the surprising solution dynamics observed by 19F NMR

“…In 1994, the same trifluoroethylating agent was prepared using the modified method by Resnati and used for Ntrifluoroethylation of amino alcohols under dry conditions [17]. In this research, novel trifluoroethylating agent (2,2,2-trifluoroethyl)phenyliodonium N,N-bis(trifluoromethylsulfonyl)imide was synthesized [8] and used for N-trifluoroethylation of a-amino acids.…”

“…Trifluoroethylating agent CF 3 CH 2 I(Ph)N(SO 2 CF 3 ) 2 was synthesized [8]. Other reagents and solvents were obtained from commercial suppliers and used without further purification.…”

“…In the past decade, we have focused on the synthesis and applications of the novel trifluoroethylating agent CF 3 CH 2 I(C 6 H 5 )N(SO 2 CF 3 ) 2 . The chemo selectivity of this agent was demonstrated by trifluoroethylation of the functionalities of a-amino acids [8][9][10]. The CF 3 CH 2 -group was introduced at the N-terminus of leucine and methionine enkephalins to improve the lipophilicity of these brain peptides.…”