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Guoyu Zhang Song Zhou Dr. Liang Fu Dr. Pinhong Chen Prof. Yibiao Li Prof. Dr. Jianping Zou Prof. Dr. Guosheng Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20619-20624
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, and give a series of chiral α-cyano amides, α-cyano esters and α-hemiaminals in good yields with excellent enantioselectivity. The chiral α-cyano amides can be easily converted into enantioenriched 1,2-diamines and amino acids. 相似文献
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采用了最近热门的Rh(III)催化C?H键活化方法,以N-甲氧基苯甲酰胺系列物为反应底物, N-氰基-N-苯基对甲苯磺酰胺(NCTS)为氰基化试剂,高效合成了含氰基官能团产物。结果表明,该反应在碳酸银存在下,使用二氧六环作为反应溶剂,于80°C反应8h生成的邻位氰基取代的N-甲氧基苯甲酰胺的产率较高。进一步研究表明,该反应具有好的区域选择性和底物/官能团适应性。一系列机理实验研究表明,该反应可能采用了一个内部的亲电取代机制及使用了C?H键切割步骤作为关键限速步骤。考虑到该反应产物包含有价值的结构单元-N-甲氧基甲酰胺和氰基取代基,因而有望用于现代有机合成中。 相似文献
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A Porous Organic Poly(triphenylimidazole) Decorated with Palladium Nanoparticles for the Cyanation of Aryl Iodides 下载免费PDF全文
Haiwen Yu Siqi Xu Dr. Yijiang Liu Prof. Hongbiao Chen Prof. Huaming Li 《化学:亚洲杂志》2018,13(18):2708-2713
A new porous organic poly(triphenylimidazole), PTPI‐Me, was prepared through a Yamamoto self‐coupling reaction of 2,4,5‐tris‐(4‐bromophenyl)‐1‐methyl‐1H‐imidazole (TPI‐Me) in the presence of bis(1,5‐cyclooctadiene)nickel(0). The polymer was subsequently decorated with Pd nanoparticles (NPs) to afford a heterogeneous cyanation catalyst, Pd@PTPI‐Me. Pd NPs with an average diameter of 2.7 nm were grown within the PTPI‐Me framework, owing to the coordination of the imidazole rings to the Pd species. The resultant Pd@PTPI‐Me catalyst, with a Pd loading of 0.13 mmol g?1, exhibited superior catalytic activity for the cyanation of aryl iodides. More importantly, the heterogeneous catalyst was also readily recycled and displayed negligible deactivation after five cycles. 相似文献
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Straightforward α‐Amino Nitrile Synthesis Through Mo(CO)6‐Catalyzed Reductive Functionalization of Carboxamides 下载免费PDF全文
Dr. Paz Trillo Dr. Tove Slagbrand Prof. Dr. Hans Adolfsson 《Angewandte Chemie (International ed. in English)》2018,57(38):12347-12351
The selective reduction of amides into an intermediate hemiaminal catalyzed by Mo(CO)6 together with the inexpensive and easy to handle TMDS (1,1,3,3‐tetramethyldisiloxane) as reducing agent, followed by subsequent trapping of the hemiaminal with a cyanide source, allows for the straightforward synthesis of α‐amino nitriles. The methodology presented here, displays high levels of chemoselectivity allowing for the reduction of amides in the presence of functional groups such as ketones, imines, aldehydes, and acids, which affords a simple route for the synthesis of α‐amino nitriles with a broad scope of functionalities in high yields. Furthermore, the applicability of this methodology is demonstrated by scale up experiments and by derivatization of the target compounds into synthetically interesting products. The selective cyanation is successfully applied in late stage functionalizations of amide containing drugs and prolinol derivatives. 相似文献
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研究考察了在手性(salen)AlCl-叶立德络合物(R,R)-1/2a作为催化剂和异丙醚作为溶剂的条件下,两种不同硅氰化试剂[Me2(CH2Cl)SiCN和Me3SiCN(TMSCN)]在对醛的不对称氰化中的应用情况.一系列不同取代的芳香醛均可分别与这两种试剂发生反应,以高到优秀的产率和对映选择性得到目标产物.脂肪醛的反应产物的对映选择性最高只能达到中等.对比研究发现,Me2(CH2Cl)SiCN在醛的硅氰化反应中显示出了明显高于TMSCN的反应活性,但是产物的对映选择性大体相当. 相似文献
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