首次报道了使用HCO 2 H / NEt 3作为还原剂的钌(II)催化的酰胺脱氧转移胺成胺。催化剂体系由[Ru(2-甲基烯丙基)2(COD)],1,1,1-三(二苯基膦甲基)乙烷(triphos)和双(三氟甲烷磺酰亚胺)(HNTf 2)在将各种仲酰胺和叔酰胺脱氧还原成相应的胺方面表现出色,选择性极好,并且对包括还原敏感基团在内的官能团表现出很高的耐受性。氢源和酸助催化剂的选择对于催化至关重要。机理研究表明,通过借入氢对原位生成的醇和胺进行还原胺化是主要途径。
The first B(C6F5)3‐catalyzed deoxygenative reduction of amides into the corresponding amines with readily accessible and stable ammonia borane (AB) as a reducing agent under mild reaction conditions is reported. This metal‐free protocol provides facile access to a wide range of structurally diverse amine products in good to excellent yields, and various functional groups including those that are reduction‐sensitive
据报道,在温和的反应条件下,用易于获得且稳定的氨硼烷(AB)作为还原剂,将酰胺进行的首次B(C 6 F 5)3催化脱氧还原为相应的胺。该无金属方案可轻松获得各种结构多样的胺产品,且收率高至优异,并且对各种官能团(包括对还原敏感的官能团)均具有良好的耐受性。该新方法也适用于手性酰胺底物,而不会破坏对映体的纯度。BF 3 OEt 2助催化剂在该反应中的作用是通过酰胺-硼加合物的原位形成来活化酰胺羰基。
Boron Lewis Acid Promoted Ruthenium-Catalyzed Hydrogenation of Amides: An Efficient Approach to Secondary Amines
作者:Ming-Lei Yuan、Jian-Hua Xie、Qi-Lin Zhou
DOI:10.1002/cctc.201600635
日期:2016.10.6
The hydrogenation of amides to amines has been developed by using the catalyst [Ru(H)2(CO)(Triphos)] (Triphos=1,1,1‐tri(diphenylphosphinomethyl)ethane) and catalytic boron Lewis acids such as B(C6F5)3 or BF3⋅Et2O as additives. The reaction provides an efficient method for the preparation of secondary amines from amides in good yields with high selectivity.
Solvent-Free Iron(III) Chloride-Catalyzed Direct Amidation of Esters
作者:Blessing D. Mkhonazi、Malibongwe Shandu、Ronewa Tshinavhe、Sandile B. Simelane、Paseka T. Moshapo
DOI:10.3390/molecules25051040
日期:——
work, we report the synthesis of these functional groups via an iron(iii) chloride-catalyzed direct amidation of esters. The reactions are conducted under solvent-free conditions and found to be compatible with a range of amine and ester substrates generating the desired amides in short reactiontimes and good to excellent yields at a catalyst loading of 15 mol%.
N,2-Dilithioalkylamines from Aziridines by Naphthalene-Catalyzed Reductive Opening. Synthetic Applications
作者:Juan Almena、Francisco Foubelo、Miguel Yus
DOI:10.1021/jo00090a044
日期:1994.6
The reductive opening of aziridines 1a-c with lithium in the presence of a catalytic amount of naphthalene at -78 degrees C led to the corresponding dianionic intermediates 2a-c, which are stable species under these reaction conditions and react with electrophilic reagents [H2O, D2O, Me(2)S(2), Bu(t)CHO, PhCHO, Me(2)CO, (CH2)(5)CO, (EtO)(2)CO, CH2=CHCO(2)Me, PhCON(CH2)(4), PhCH=NPh, MeI, and CH2=CHCH2Br] to give, after hydrolysis with water, the corresponding difunctionalized compounds 3-5. When the reductive opening and the reaction with electrophiles [H2O, D2O, CH2=CHCH2Br, Me(2)CO, (c-C3H5)(2)CO] were carried out on chiral aziridines 8 and 9, enantiomerically pure difunctionalized compounds 12 were obtained with same stereochemistry, independently of the stereochemistry of diastereomeric starting aziridines 8 and 9.