6634-17-9Relevant articles and documents
Demethylative Alkylation of Methionine Residue by Employing the Sulfonium as the Key Intermediate
Chan, Albert S. C.,Ge, Yang,Hu, Qi-Long,Li, Jian,Liu, Jia-Tian,Song, Zhendong,Xiong, Xiao-Feng
supporting information, p. 8543 - 8548 (2021/11/13)
Methionine (Met) offers a valuable handle to achieve peptide chemical modification owing to its unique thioether functional group. In contrast with cysteine, the site-selective functionalization of the hydrophobic and redox-sensitive thioether motif on peptides is still challenging, and strategies for diversification on the Met residue are rarely disclosed. Herein we report a transition-metal-free and redox-neutral approach for Met diversification with substrate diversity, which could be applied to synthesize cyclic peptides.
The decomposition of ethyl diazoacetate over zeolite NaCuX
Oudejans, J. C.,Kaminska, J.,Bekkum, H. van
, p. 537 - 541 (2007/10/02)
The decomposition of ethyl diazoacetate catalyzed by Cu(II)-exchanged zeolite NaX, has been studied.Catalytic activity required at least 25 percent sodium exchange of the zeolite.From 25 percent exchange to higher levels the decomposition rate increased linearly with the copper introduced into the zeolite.With cyclohexane as the solvent, the (ethoxycarbonyl)carbene formed was found to yield dimers, diethyl maleate and diethyl fumarate, and also compounds resulting from reaction with the solvent or with residual water present in the zeolite.Reduction of Cu(II) to Cu(I) increased the activity of the catalysts.The degree of hydration of the zeolite had a large effect on the activity of the catalyst and on the selectivity of the reaction.Complexation of the Cu(II) ions with NH3 or 1,2-propanediamine reduced the activity of the zeolite drastically.Zeolite NaCuX showed no induction time in contrast to several copper salts tested.
