Regioselective, Photocatalytic α-Functionalization of Amines
摘要:
Photocatalytic alpha-functionalization of amines provides a mild and atom-economical means to synthesize alpha-branched amines. Prior examples featured symmetrical or electronically biased substrates. Here we report a controllable alpha-functionalization of amines in which regioselectivity can be tuned with minor changes to the reaction conditions.
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。
Ru‐Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
ruthenium(II)‐catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2‐methylallyl)2(COD)], 1,1,1‐tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding
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。
General Reductive Amination of Aldehydes and Ketones with Amines and Nitroaromatics under H<sub>2</sub>
by Recyclable Iridium Catalysts
applied for the reductiveamination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid 1‐methyl‐3‐cyanomethylimidazoulium chloride ([MCNI]Cl) with iridium chloride (IrCl3) in activatedcarbons. Iridium particles were well dispersed and stable in the N‐doped carbon materials from [MCNI]Cl with activatedcarbon. The Ir@NC(600‐2h)
Reverse Polarity Reductive Functionalization of Tertiary Amides via a Dual Iridium-Catalyzed Hydrosilylation and Single Electron Transfer Strategy
作者:Tatiana Rogova、Pablo Gabriel、Stamatia Zavitsanou、Jamie A. Leitch、Fernanda Duarte、Darren J. Dixon
DOI:10.1021/acscatal.0c03089
日期:2020.10.2
amide buildingblocks has been developed. By combining Vaska’s complex-catalyzed tertiary amide reductive activation and photochemical single electron reduction into a streamlined tandem process, metastable hemiaminal intermediates were successfully transformed into nucleophilic α-amino free radical species. This umpolung approach to such reactive intermediates was exemplified through coupling with