Continuous-flow processes for the <i>S</i>-alkynylation of cysteine-containing peptides and thioglycosides under catalyst-free, oxidant-free and mild conditions
Selective S-alkynylation of cysteine-containing peptides and 1-thioglycoside residues was developed using continuous flow.
含半胱氨酸肽和1-硫代糖苷残基的选择性S-炔基化反应已经在连续流条件下开发。
Enantioselective Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds
作者:Durga Prasad Hari、Jerome Waser
DOI:10.1021/jacs.7b04756
日期:2017.6.28
Enantioselective catalytic methods allowing the addition of both a nucleophile and an electrophile onto diazocompounds give a fast access into important building blocks. Herein, we report the highly enantioselective oxyalkynylation of diazocompounds using ethynylbenziodoxol-(on)e reagents and a simple copper bisoxazoline catalyst. The obtained α-benzoyloxy propargylic esters are useful building blocks
Fast and Highly Chemoselective Alkynylation of Thiols with Hypervalent Iodine Reagents Enabled through a Low Energy Barrier Concerted Mechanism
作者:Reto Frei、Matthew D. Wodrich、Durga Prasad Hari、Pierre-Antoine Borin、Clément Chauvier、Jérôme Waser
DOI:10.1021/ja5083014
日期:2014.11.26
Nevertheless, general methods to access these compounds are lacking. In this article, we describe the mechanism and full scope of the alkynylation of thiols using ethynyl benziodoxolone (EBX) hypervalent iodine reagents. Computations led to the discovery of a new, three-atom concerted transition state with a very low energy barrier, which rationalizes the high reaction rate. On the basis of this result
Ethynylbenziodoxolones (EBX) as Reagents for the Ethynylation of Stabilized Enolates
作者:Davinia Fernández González、Jonathan P. Brand、Régis Mondière、Jérôme Waser
DOI:10.1002/adsc.201300266
日期:2013.5.17
with ethynylbenziodoxolone (EBX) reagents. The structure and stability of this class of reagents is first described more in details. Differential scanning calorimetry (DSC) experiments showed a strong exothermic decomposition with EBXreagents, leading to guidelines for the safe use of these compounds. The extension of the method to aromatic alkynes and a broad range of benziodoxol(on)e reagents is then
在此,我们报告的环酮酯和酰胺的电炔基随着研究的深入ê thynyl b enziodo X olone(EBX)试剂。首先更详细地描述这类试剂的结构和稳定性。差示扫描量热法(DSC)实验表明,使用EBX试剂会发生强烈的放热分解,从而为安全使用这些化合物提供了指导。然后报道了将该方法扩展到芳族炔烃和广泛的苯并齐多酚(on)e试剂。根据我们使用Cinchona的初步结果基于相转移催化剂,可以实现环酮酯的对映选择性炔基化。由Maruoka和他的同事开发的由联萘胺衍生的铵催化剂提供了最高的不对称诱导率,对于茚满酮衍生的酮酯,ee高达79%。在整个工作过程中,仅在苯并恶唑酮试剂中观察到不对称诱导,证明了它们优于常规烷基炔诺酮盐。对导致更高的不对称诱导的因素的更深入的了解将在将来开发一种真正通用的和高度对映选择性的炔基化方法中非常有用。
Ethynyl Benziodoxolones for the Direct Alkynylation of Heterocycles: Structural Requirement, Improved Procedure for Pyrroles, and Insights into the Mechanism
作者:Jonathan P. Brand、Clara Chevalley、Rosario Scopelliti、Jérôme Waser
DOI:10.1002/chem.201200200
日期:2012.4.27
accelerating effect of a methyl substituent in both the 3‐ and 6‐position of triisopropylsilylethynyl‐1,2‐benziodoxol‐3(1H)‐one (TIPS‐EBX) on the reaction rate was observed. Competitive experiments between substrates of different nucleophilicity, deuterium labeling experiments, as well as the regioselectivity observed are all in agreement with electrophilic aromatic substitution. Gold(III) 2‐pyridinecarboxylate