Application of Silicon-Initiated Water Splitting for the Reduction of Organic Substrates
作者:Ashot Gevorgyan、Satenik Mkrtchyan、Tatevik Grigoryan、Viktor O. Iaroshenko
DOI:10.1002/cplu.201800131
日期:2018.5
several important classes of organic compounds is described. It is found that the reductive water splitting can be promoted by several metalloids among which silicon shows the best efficiency. The developed methodologies were applied for the reduction of nitro compounds, N-oxides, sulfoxides, alkenes, alkynes, hydrodehalogenation as well as for the gram-scale synthesis of several substrates of industrial
Fe2O3-supported nano-gold catalyzed one-pot synthesis of N-alkylated anilines from nitroarenes and alcohols
作者:Qiling Peng、Yan Zhang、Feng Shi、Youquan Deng
DOI:10.1039/c1cc11057h
日期:——
Here, we show the one-step synthesis of N-alkylated anilines from nitrobenzenes and alcohols catalyzed by nano-gold catalyst. The yields to N-alkylated anilines were ∼90% under mild conditions. The mechanism of this reaction was explored. It shows promise for clean and simple synthesis of N-alkylated anilines.
Kinetics and mechanism of the anilinolysis of<i>S</i>-aryl<i>N</i>-arylthiocarbamates in acetonitrile
作者:Dae Dong Sung、Hee Man Jang、Dae Il Jung、Ikchoon Lee
DOI:10.1002/poc.1418
日期:2008.11
values that are consistent for a stepwise mechanism with rate-limiting formation of the zwitterionic tetrahedral intermediate. Signs of cross-interaction constants, ρXY (>0), ρXZ (>0) and ρYZ (<0), are all consistent with a stepwise mechanism. It is concluded that the change of the amine from benzylamines to anilines causes a shift of the aminolysis mechanism from a concerted to a stepwise process. Copyright
Catalytic Enantioselective Synthesis of Heterocyclic Vicinal Fluoroamines by Using Asymmetric Protonation: Method Development and Mechanistic Study
作者:Matthew W. Ashford、Chao Xu、John J. Molloy、Cameron Carpenter‐Warren、Alexandra M. Z. Slawin、Andrew G. Leach、Allan J. B. Watson
DOI:10.1002/chem.202002543
日期:2020.9.21
A catalytic enantioselective synthesis of heterocyclic vicinal fluoroamines is reported. A chiral Brønsted acid promotes aza‐Michael addition to fluoroalkenyl heterocycles to give a prochiral enamine intermediate that undergoes asymmetric protonation upon rearomatization. The reaction accommodates a range of azaheterocycles and nucleophiles, generating the C−F stereocentre in high enantioselectivity
报道了杂环邻位氟胺的催化对映选择性合成。手性布朗斯台德酸促进氮杂-迈克尔加成到氟链烯基杂环上,从而得到手性烯胺中间体,该中间体在重新芳构化后经历不对称的质子化。该反应可容纳一定范围的氮杂杂环和亲核试剂,以高对映选择性生成C-F立体中心,并且还适合立体C-CF 3债券。大量的DFT计算为速率控制步骤中质子从催化剂到底物的立体控制转移提供了证据,并表明了催化剂烷基的空间相互作用在增强高对映选择性中的重要性。晶体结构数据显示了核心结构构象中非共价相互作用的优势,从而能够调节构象态势。Ramachandran类型的构象异构体分布分析和Protein Data Bank挖掘表明,这种方法的苄基氟化有可能提高几种市售药物的效力。
Kinetics and Mechanism of the Anilinolysis of Dibutyl Chlorothiophosphate in Acetonitrile
作者:Md. Ehtesham Ul Hoque、Hai-Whang Lee
DOI:10.5012/bkcs.2012.33.3.843
日期:2012.3.20
The nucleophilic substitution reactions of dibutyl chlorothiophosphate (4S) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs;$k_H/k_D$) are primary normal ($k_H/k_D$ = 1.10-1.35). A concerted mechanism involving predominant frontside nucleophilic attack is proposed on the basis of the primary normal DKIEs and selectivity parameters. Hydrogen bonded, four-center-type transition state is proposed. The steric effects of the two ligands on the anilinolysis rates of the chlorothiophosphates are discussed. The anilinolyses of P=S systems are compared with those of their P=O counterparts on the basis of the reactivities, thio effects, selectivity parameters, and DKIEs.