The carboxyl group (COOH) is an omnipresent functional group in organic molecules, and its direct catalytic activation represents an attractive synthetic method. Herein, we describe the first example of a direct catalytic nucleophilic activation of carboxylicacids with BH3·SMe2, after which the acids are able to act as carbon nucleophiles, i.e. enolates, in Mannich-type reactions. This reaction proceeds
Organocatalytic Enantioselective Synthesis of α-Fluoro-β-amino Acid Derivatives
作者:Matthew R. Straub、Vladimir B. Birman
DOI:10.1021/acs.orglett.8b03297
日期:2018.12.7
catalyst HBTM-2 generates 3-fluoro-β-lactams with high enantio- and diastereoselectivity. These reactive compounds are opened with alcohols or amines to produce the corresponding α-fluoro-β-amino acid derivatives in moderate yields.
The first nickel(0)-catalyzed [2 + 2 + 1] carbonylative cycloaddition reaction of imines and alkynes or norbornene has been achieved by employing phenyl formate as a CO source. With this method, a variety of N-benzenesulfonyl, -tosyl, and -phosphoryl-substituted γ-lactams can be prepared in good to high yields.
The use of samarium or sodium iodide salts as an alternative for the aza-Henry reaction
作者:Humberto Rodríguez-Solla、Carmen Concellón、Noemí Alvaredo、Raquel G. Soengas
DOI:10.1016/j.tet.2011.12.061
日期:2012.2
A novel reaction of bromonitromethane with a variety of imines in very mild conditions promoted by SmI2 and NaI to afford nitroamines or bromonitroamines is described. When these reactions were performed on sugar-based imines, the corresponding nitroamines or bromonitroamines were obtained in high yields and from moderate to good stereoselectivities. Synthetic possibilities of nitroamines were also
描述了由SmI 2和NaI促进的在非常温和的条件下溴硝基甲烷与各种亚胺的新颖反应,以提供硝基胺或溴硝基胺。当对基于糖的亚胺进行这些反应时,以高收率和中等至良好的立体选择性获得了相应的硝胺或溴硝胺。硝基胺在室温下在吡咯烷存在下用SmI 2 / H 2 O还原也显示出合成的可能性。提出了这种新颖的氮杂-亨利反应的机理。
Aza-Morita–Baylis–Hillman reactions catalyzed by a cyclopropenylidene
作者:Xun Lu、Uwe Schneider
DOI:10.1039/c6cc06201f
日期:——
Catalysis using a bis(dialkylamino)cyclopropenylidene (BAC) has been developed, which relies on a formal umpolung activation of Michael acceptor pro-nucleophiles.