Electrophilic<i>S</i>-Trifluoromethylation of Cysteine Side Chains in<i>α</i>- and<i>β</i>-Peptides: Isolation of Trifluoro-methylated<i>Sandostatin</i><sup>®</sup>(Octreotide) Derivatives
作者:Stefania Capone、Iris Kieltsch、Oliver Flögel、Gerald Lelais、Antonio Togni、Dieter Seebach
DOI:10.1002/hlca.200890217
日期:2008.11
The new electrophilic trifluoromethylating 1-(trifluoromethyl)-benziodoxole reagents A and B (Scheme 1) have been used to selectively attach CF3 groups to the S-atom of cysteine side chains of α- and β-peptides (up to 13-residues-long; products 7–14). Other functional groups in the substrates (amino, amido, carbamate, carboxylate, hydroxy, phenyl) are not attacked by these soft reagents. Depending
新型亲电子三氟甲基化的1-(三氟甲基)-苯并恶唑试剂A和B(方案1)已用于将CF 3基团选择性连接至α-和β-肽半胱氨酸侧链的S原子(最多13个残基) -长;产品7 – 14)。底物中的其他官能团(氨基,酰胺基,氨基甲酸酯,羧酸根,羟基,苯基)不受这些软试剂的攻击。取决于条件,Trp残基的吲哚环也可以被三氟甲基化(在2-位)。产物经色谱纯化,用1 H-鉴定,13 C和19 F-NMR光谱,CD光谱和高分辨率质谱法。如此引入的CF 3基团可以被H(Na / NH 3)代替,其是总的Cys / Ala转化率。讨论了三氟甲基化在药物化学中的重要性以及该方法的可能应用(旋转标记,成像,PET)。