Phototriggered Dehydration Condensation Using an Aminocyclopropenone
摘要:
A phototriggered dehydration condensation using an aminocyclopropenone has been developed. The UV irradiation of an, aminocyclopropenone generated a highly reactive ynamine in situ and the dehydration condensation of a carboxylic acid and an amine coexisting in the reaction solution smoothly proceeded to afford an amide. This reaction is completely controllable by the ON/OFF states of a UV lamp.
A direct amidation of carboxylicacids with tertiary amines could be carried out in the presence of the Ph3P–I2 activator. With an appropriate reagent addition sequence, a range of carboxylicacids including aliphatic, allylic, and aromatic acids could be converted into their corresponding tertiary amides under mild conditions without requirement of metal catalysis.
catalyst towards amidation of a wide range of alcohols with amines. Three newair-stable Ruthenium(II) complexes bearing bis-phenolate-N-heterocyclic carbene ligand were synthesized and characterized by FT-IR, NMR and ESI-Mass. The catalytic study of these complexes towards amidation of alcohol with amines was conducted. This new protocol is effective for many electronically diverse alcohols and amines
本贡献描述了由双酚盐-N-杂环卡宾[ t Bu(OCO)2- ](NHC)类型的三齿钳状配体支持的一族坚固的钌配合物的合成和表征。通过咪唑啉鎓配体(HL)与金属前体[RuHCl(CO)(EPh 3)2(B)的反应,以高收率合成了带有双酚盐-N-杂环卡宾配体的钌(II)配合物(1-3)。 ](E = P或As; B = PPh 3,AsPh 3或Py)从相应的银卡宾络合物中进行金属转移。所有的Ru(II)-NHC配合物均已通过元素分析,光谱方法以及ESI质谱进行了表征。根据光谱结果,为所有配合物分配了八面体几何形状。t Bu(OCO)2-配体的三齿性质以及t Bu基团提供的一定水平的空间保护可合理化本系统中Ru-C卡宾键的出色稳定性。此外,为了探索合成化合物的催化潜力,所有三种[Ru-NHC]配合物(1-3)被用作乙醇与胺酰胺化的催化剂。值得注意的是,发现配合物1对于将多种醇与胺酰胺化是非常有效和通用的催化剂。
Enantioselective Synthesis of α‐Aryl‐β
<sup>2</sup>
‐Amino‐Esters by Cooperative Isothiourea and Brønsted Acid Catalysis
作者:Feng Zhao、Chang Shu、Claire M. Young、Cameron Carpenter‐Warren、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/anie.202016220
日期:2021.5.17
The synthesis of α‐aryl‐β2‐amino esters through enantioselective aminomethylation of an arylacetic acid ester in high yields and enantioselectivity via cooperative isothiourea and Brønsted acid catalysis is demonstrated. The scope and limitations of this process are explored (25 examples, up to 94 % yield and 96:4 er), with applications to the synthesis of (S)‐Venlafaxine⋅HCl and (S)‐Nakinadine B.
证明了通过异硫脲和布朗斯台德酸协同催化,对芳基乙酸酯进行对映选择性氨甲基化,以高收率和对映选择性合成α-芳基-β 2 -氨基酯。探索了该过程的范围和局限性(25 个示例,产率高达 94% 和 96:4 er),并应用于 ( S )-文拉法辛·HCl 和 ( S )-Nakinadine B的合成。机理研究是一致的遵循 C(1)-烯醇化铵途径,而不是替代的动态动力学解析过程。对照研究表明 (i) 观察到催化剂和产物 er 之间存在线性效应;(ii)酰基铵离子可以用作预催化剂;(iii)可逆的异硫脲加成到原位生成的亚胺离子上,产生可用作生产性预催化剂的非循环中间体。
Solvent-Free N-Alkylation of Amides with Alcohols Catalyzed by Nickel on Silica-Alumina
作者:Aubin Charvieux、Louis Le Moigne、Lorenzo G. Borrego、Nicolas Duguet、Estelle Métay
DOI:10.1002/ejoc.201901291
日期:2019.10.31
To date, the N‐alkylation of amides with alcohols has not been studied with non‐noble metal base heterogeneous catalyst. Herein, a range of amide was efficiently N‐alkylated with various alcohols using cheap and easy to handle Ni/SiO2‐Al2O3.
迄今为止,尚未使用非贵金属碱多相催化剂研究酰胺与醇的N-烷基化。在此,使用廉价且易于处理的Ni / SiO 2 -Al 2 O 3将各种酰胺有效地与各种醇进行N-烷基化。
Direct Synthesis of Amides from Carboxylic Acids and Amines Using B(OCH<sub>2</sub>CF<sub>3</sub>)<sub>3</sub>
作者:Rachel M. Lanigan、Pavel Starkov、Tom D. Sheppard
DOI:10.1021/jo400509n
日期:2013.5.3
range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amino acids with both primary and secondary amines proceeds effectively, with very low levels of racemization. B(OCH2CF3)3 can also be used for the formylation of a range of amines in good