Silver-Catalyzed [3+2] Cycloaddition of Azomethine Ylides with Isocyanides for Imidazole Synthesis
作者:Zhongyan Hu、Jinhuan Dong、Xianxiu Xu
DOI:10.1002/adsc.201700447
日期:2017.10.25
silver-catalyzed aerobic oxidative [3+2] cycloaddition of azomethineylides with aryl or heteroaryl isocyanides has been developed. The reaction represents a novel protocol for the efficient and practical synthesis of 1,2-diarylimidazoles bearing a broad range of substituents in good to excellent yields under mild conditions. The practicability of this cycloaddition was shown by a gram-scale synthesis
Three-Component, Diastereoselective [6 + 3] Annulation of Tropone, Imino Esters, and Arynes
作者:Avishek Guin、Rahul N. Gaykar、Shiksha Deswal、Akkattu T. Biju
DOI:10.1021/acs.orglett.1c02662
日期:2021.10.1
diastereoselective [6 + 3] annulation reaction employing tropone, imino esters, and arynes allowing the synthesis of bridged azabicyclo[4.3.1]decadienes is demonstrated. The key nitrogen ylides for the [6 + 3] annulation were generated by the addition of imino esters to the arynes followed by a proton transfer. The nitrogen ylides undergo a regioselective addition to tropone to furnish the desired products in moderate
Nef Reaction of Nitropyrrolidines: Novel Synthesis of Hydroxypyrrolidine Derivatives
作者:Miklós Nyerges、Chwang Pak
DOI:10.1055/s-2007-985583
日期:2007.9
A general synthetic route to hydroxypyrrolidine derivatives using the first Nefreaction of nitropyrrolidines with chromium(II) chloride as a key step is presented.
介绍了使用硝基吡咯烷与氯化铬 (II) 的第一次 Nef 反应作为关键步骤的羟基吡咯烷衍生物的一般合成路线。
METHOD FOR PRODUCING OPTICALLY ACTIVE 1-AMINO-2-VINYLCYCLOPROPANECARBOXYLIC ACID ESTER
申请人:Aikawa Toshiaki
公开号:US20120130116A1
公开(公告)日:2012-05-24
1-Amino-2-vinylcyclopropanecarboxylic acid ester, which is useful as a synthetic intermediate of pharmaceuticals, can be produced by a process of producing 1-amino-2-vinylcyclopropanecarboxylic acid ester represented by formula (4):
including a step of hydrolysis of an optically active 1-N-(arylmethylene)amino-2-vinylcyclopropanecarboxylic acid ester represented by formula (3):
which is obtained by reacting an N-(arylmethylene)glycine ester represented by formula (1):
with a compound represented by formula (2):
in the presence of a base and an optically active quaternary ammonium salt.
PROCESS FOR PRODUCTION OF MONO-SUBSTITUTED ALKYLATED COMPOUND USING ALDIMINE OR DERIVATIVE THEREOF
申请人:Maruoka Keiji
公开号:US20090054679A1
公开(公告)日:2009-02-26
The present invention provides a method for producing asymmetrical mono-substituted alkylated compounds of α-amino acids that are represented by a specific formula, using an aldimine-type Schiff base. In the method of the present invention, the process of alkylating an aldimine-type Schiff base in a medium in the presence of an optically-active quaternary ammonium salt phase-transfer catalyst and an inorganic base is initiated, and subsequently the reaction is quenched at a time earlier than a time for completion of the stoichiometric reaction of the alkylation reaction, so that a mono-substituted alkylated product with high optical purity can be obtained.