Asymmetric Coupling of Carbon‐Centered Radicals Adjacent to Nitrogen: Copper‐Catalyzed Cyanation and Etherification of Enamides
作者:Guoyu Zhang、Song Zhou、Liang Fu、Pinhong Chen、Yibiao Li、Jianping Zou、Guosheng Liu
DOI:10.1002/anie.202008338
日期:2020.11.9
The first copper‐catalyzed asymmetric cyanation and etherification reactions of enamides have been established, where a carbon‐centered radical adjacent to a nitrogen atom (CRAN) is enantioselectively trapped by a chiral copper(II) species. Moreover, the asymmetric cyanation of vinyl esters was disclosed as well. These reactions feature very mild reaction conditions and high functional group tolerance
Regio‐ and Stereoselective Chan‐Lam‐Evans Enol Esterification of Carboxylic Acids with Alkenylboroxines
作者:Luuk Steemers、Linda Wijsman、Jan H. van Maarseveen
DOI:10.1002/adsc.201800914
日期:2018.11.5
Efficient and scalable Cu(II)‐mediated enol esterification methodology of carboxylicacids from alkenyl boroxines and boronic acids is presented. The reaction shows a wide scope in aliphatic and aromatic carboxylicacids in combination with several alkenyl boroxines. In the case of 2‐substituted alkenyl boroxines the double bond configuration was fully retained in the enol ester product. Also N‐hydroxyimides
Method for preparing ester linked peptide-carbohydrate conjugates
申请人:——
公开号:US20040208883A1
公开(公告)日:2004-10-21
A method of producing an ester linked carbohydrate-peptide conjugate is provided comprising: (a) providing a vinyl ester amino acid group, and (b) reacting the vinyl ester amino acid with a carbohydrate acyl acceptor in the presence of an enzyme, to produce thereby an ester-linked carbohydrate-peptide conjugate. Also provided are ester linked carbohydrate-peptide conjugates obtainable by such methods.
the first biocatalytic modification of sesquiterpenelactones (STL) found in chicory plants. Regioselective O-acylation of their primary alcohol group is achieved by the immobilized lipase B from Candida antarctica, with various aliphatic vinyl esters as acyl donors. High conversion rates were observed, facilitating the synthesis of novel semi-synthetic STL ester derivatives with promising pharmaceutical
本文报道了在菊苣植物中发现的倍半萜内酯 (STL) 的首次生物催化修饰。其伯醇基团的区域选择性O-酰化是通过来自南极假丝酵母的固定化脂肪酶 B 以各种脂肪族乙烯基酯作为酰基供体实现的。观察到高转化率,促进了具有良好药物应用前景的新型半合成STL酯衍生物的合成。
Ready protease-catalyzed synthesis of carbohydrate–amino acid conjugates
作者:Viviane Boyer、Benjamin G. Davis、Mincho Stanchev、Antony J. Fairbanks
DOI:10.1039/b104137c
日期:——
The protease-catalyzed synthesis of amino acid
esterâcarbohydrate conjugates as glycopeptide analogues has been
achieved in a highly regioselective and carbohydrate-specific manner using
amino acid vinyl ester acyl donors and minimally or completely unprotected
carbohydrate acyl acceptors, which together probed active sites of
proteases to reveal yield efficiencies that are modulated by the
carbohydrate C-2 substituent, and that may be exploited to allow selective
one-pot syntheses.