37883-45-7Relevant articles and documents
Alkali-metal hexamethyldisilazide initiated polymerization on alpha-amino acid N-substituted N-carboxyanhydrides for facile polypeptoid synthesis
Wu, Yueming,Zhou, Min,Chen, Kang,Chen, Sheng,Xiao, Ximian,Ji, Zhemin,Zou, Jingcheng,Liu, Runhui
supporting information, p. 1675 - 1678 (2021/03/15)
Polypeptoids have been explored as mimics of polypeptides, owing to polypeptoids’ superior stability upon proteolysis. Polypeptoids can be synthesized from one-pot ring-opening polymerization of amino acid N-substituted N-carboxyanhydrides (NNCAs). However, the speed of polymerization of NNCAs can be very slow, especially for NNCAs bearing a bulky N-substitution group. This hindered the exploration on polypeptoids with more diverse structures and functions. Therefore, it is in great need to develop advanced strategies that can accelerate the polymerization on inactive NNCAs. Hereby, we report that lithium/sodium/potassium hexamethyldisilazide (Li/Na/KHMDS) initiates a substantially faster polymerization on NNCAs than do commonly used amine initiators, especially for NNCAs with bulky N-substitution group. This fast NNCA polymerization will increase the structure diversity and application of polypeptoids as synthetic mimics of polypeptides.
Carbene Transfer and Carbene Insertion Reactions Catalyzed by a Mixed-Ligand Copper(I) Complex
Brenna, Stefano,Ardizzoia, G. Attilio
, p. 3336 - 3342 (2018/07/13)
The catalytic activity of the mixed-ligand copper(I) complex [Cu(PPh3)2(κ2-O,O"-lact)] (1) {lact = l-(+)-lactate} has been investigated in carbene transfer and carbene insertion reactions. Complex 1 catalytically promoted the diastereoselective cyclopropanation of olefins in the presence of ethyl diazoacetate (EDA), under mild conditions, and with a low catalyst loading (1 mol-%). In the case of internal alkenes, a trans/cis ratio of up to 93:7 was reached. Moreover, compound 1 easily promoted the insertion of the carbene fragment deriving from the decomposition of ethyl diazoacetate into O–H (alcohols and phenols) and N–H (amine) bonds, with formation of the corresponding ethyl 2-alkoxyacetate, ethyl 2-phenoxyacetate, and ethyl 2-aminoacetate derivatives in good to high yields.
Polymer-supported ruthenium(II)/phenyloxazoline complex: Reusable and highly selective catalyst for N-H insertion reactions
Abu-Elfotoh, Abdel-Moneim
, p. 349 - 352 (2017/01/24)
A group of functionalized β-amino esters were successfully synthesized in excellent yields (> 99 %) via NH-insertion of ethyldiazoacetate into various amines catalyzed by porous-polymer-supported ruthenium(II)-pheox catalyst. The catalyst was readily recovered and reused at least five times without loss of its catalytic activity.