NHC-catalyzed C–O or C–N bond formation: efficient approaches to α,β-unsaturated esters and amides
作者:Bo Zhang、Peng Feng、Yuxin Cui、Ning Jiao
DOI:10.1039/c2cc32862c
日期:——
Simple and efficient NHC-catalyzed transformations of bromoenal or α,β-dibromoenal into α,β-unsaturated esters or amides with high stereoselectivity through CâO or CâN bond formation have been demonstrated. The NHC-catalyzed processes occur under mild conditions. The ready availability of the starting materials, avoidance of external oxidants and the usefulness of the products all make the strategy attractive.
Synthesis and Reactions of 2-Substituted Ethyl <i>N</i>-Alkylmalonylhydroxamic Acids
作者:Robert V. Hoffman、Sachin Madan
DOI:10.1021/jo0300690
日期:2003.6.1
Alkylation of O-silylated N-alkylmalonylhydroxamic acids provides a method for the synthesis of 2-substituted N-alkylmalonyl hydroxamic acids. The substituent at C-2 does not materially change the chemistry of the alpha-lactam intermediates produced from them. They can be converted to unsymmetric ureas and hydantoins in high yields. The addition of unsaturated substituents at C-2 is used to produce
A mild and efficient reaction for conversion of carboxylic acids into acid bromides with ethyl tribromoacetate/triphenylphosphine under acid-free conditions
作者:Dong Ho Kang、Tae Young Joo、Eun Hwa Lee、Skaydaw Chaysripongkul、Warinthorn Chavasiri、Doo Ok Jang
DOI:10.1016/j.tetlet.2006.06.013
日期:2006.8
Acid bromides were prepared efficiently from carboxylic acids with readily available ethyl tribromoacetate and triphenylphosphine at room temperature under neutral conditions. The present process is applicable to the preparation of various acid bromides from aromatic and aliphatic carboxylic acids. Aromatic carboxylic acids were found to be more reactive than aliphatic carboxylic acids under reaction
Enhancing the Scope of the Diels–Alder Reaction through Isonitrile Chemistry: Emergence of a New Class of Acyl-Activated Dienophiles
作者:Steven D. Townsend、Xiangyang Wu、Samuel J. Danishefsky
DOI:10.1021/ja303876e
日期:2012.6.27
valuable family of dienophiles for servicing Diels-Alderreactions. These systems are assembled through extension of recently discovered isonitrile chemistry to the domain of α,β-unsaturated acids. Cycloadditions are facilitated by Et(2)AlCl, presumably via chelation between the two carbonyl groups of the N-formyl amide. Applications of the isonitrile/Diels-Alder logic to the IMDA reaction, as well as methodologies
A General and Selective Iron-Catalyzed Aminocarbonylation of Alkynes: Synthesis of Acryl- and Cinnamides
作者:Katrin Marie Driller、Saisuree Prateeptongkum、Ralf Jackstell、Matthias Beller
DOI:10.1002/anie.201005823
日期:2011.1.10
Entering the iron age: The first general method for iron‐catalyzed monocarbonylation of alkynes has been developed. A range of structurally diverse cinnamides and acrylamides have been obtained smoothly starting from commercially available amines and alkynes in the presence of [Fe3(CO)12] and ligand L (see scheme). The method is highly chemo‐ and regioselective and requires no expensive catalyst.