Enantioselective Synthesis of Hemiaminals via Pd-Catalyzed C–N Coupling with Chiral Bisphosphine Mono-oxides
摘要:
A novel approach to hemiaminal synthesis via palladium-catalyzed C-N coupling with chiral bisphosphine mono-oxides is described. This efficient new method exhibits a broad scope, provides a highly efficient synthesis of HCV drug candidate elbasvir, and has been applied to the synthesis of chiral N,N-acetals.
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。
Preparation of sugar-derived 1,2-diamines via indium-catalyzed aza-Henry-type reaction: application to the synthesis of 6-amino-1,6-dideoxynojirimycin
作者:Raquel G. Soengas、Artur M.S. Silva
DOI:10.1016/j.tetlet.2013.02.041
日期:2013.4
straightforward access to β-nitroamine derivatives. The use of chiral sugar-derived imines furnished the corresponding β-nitroamines in high yields and stereoselectivities, from which the corresponding 1,2-diamines were easily obtained. The synthetic utility of the sugar-derived 1,2-diamines in the preparation of iminosugars was illustrated in a concise synthesis of 6-amino-1,6-dideoxynojirimycin.
Catalytic Enantioselective Synthesis of Lactams through Formal [4+2] Cycloaddition of Imines with Homophthalic Anhydride
作者:Claire L. Jarvis、Jennifer S. Hirschi、Mathew J. Vetticatt、Daniel Seidel
DOI:10.1002/anie.201612148
日期:2017.3.1
An amide‐thiourea compound, operating through a novel ion pairing mechanism, is an efficient organocatalyst for the asymmetric reaction of homophthalic anhydride with imines. N‐aryl and N‐alkyl imines readily undergo formal [4+2] cycloaddition to provide lactams with high levels of enantio‐ and diastereoselectivity. The nature of the key chiral ion pair intermediate was elucidated by DFT calculations
Indium-Mediated Aza-Henry Reaction of Imines: Access to 2-Nitroamines
作者:Raquel G. Soengas、Sandrina Silva、Amalia M. Estévez、Juan C. Estévez、Ramón J. Estévez、Humberto Rodríguez-Solla
DOI:10.1002/ejoc.201200304
日期:2012.8
A new method has been developed to obtain 2-nitroamines by an indium-promoted reaction of bromonitromethane with a variety of imines. On the strength of these results, the reaction was also performed with 2-bromo-2-nitropropanes to afford 2,2-dialkyl-2-nitroamines. Moreover, the indium-mediatedreaction of 1-bromo-1-nitroethane and imines afforded 1-methyl-2-nitroamines with remarkably high anti selectivity
A Modified and Highly Useful Protocol for the Brønsted Acid Catalyzed, Enantioselective, Vinylogous Mannich Reaction with Aliphatic Aldimines
作者:Christoph Schneider、Falko Abels
DOI:10.1055/s-0031-1289303
日期:2011.12
Highly enantioselective as well as diastereoselective catalytic vinylogousMannichreactions have been accomplished for the first time with aliphatic straight-chain aldimines and O,O-silylketene acetals and furnish valuable synthetic building blocks in high enantiomeric purity. vinylogousMannichreaction - phosphoric acid - organocatalyis - contact ion pair - dienolate - BINOL