Highly efficient oxidation of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives by dioxygen
摘要:
A highly efficient and environmental-benign oxidation by dioxygen (or air) as the sole oxidant was first applied for the conversion of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives in very good and excellent yields. The substituent effect on 2-imidazoline ring was investigated. This protocol was also suitable for the synthesis of 2-imidazoles in relatively large scale. (C) 2012 Elsevier Ltd. All rights reserved.
Highly Enantioselective Synthesis of (<i>S</i>)-α-Alkyl-α,β-diaminopropionic Acids via Asymmetric Phase-Transfer Catalytic Alkylation of 2-Phenyl-2-imidazoline-4-carboxylic Acid<i>tert</i>-Butyl Esters
作者:Yohan Park、Sukhoon Kang、Young Ju Lee、Taek-Soo Kim、Byeong-Seon Jeong、Hyeung-geun Park、Sang-sup Jew
DOI:10.1021/ol9013552
日期:2009.8.20
An efficient enantioselective synthetic method for (S)-α-alkyl-α,β-diaminopropionic acid is reported. The asymmetricphase-transfercatalyticalkylation of N(1)-Boc-2-phenyl-2-imidazoline-4-carboxylic acid tert -butyl ester in the presence of chiral quaternary ammonium catalyst gave the corresponding alkylated products (93−98% ee) which could be transformed to enantioenriched α-alkyl-α,β-diaminopropionic
Highly efficient oxidation of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives by dioxygen
作者:Yue Huang、Xiaodong Zu、Fan Wu、Jinyi Xu、Xiaoming Wu、Hequan Yao
DOI:10.1016/j.tet.2012.01.025
日期:2012.4
A highly efficient and environmental-benign oxidation by dioxygen (or air) as the sole oxidant was first applied for the conversion of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives in very good and excellent yields. The substituent effect on 2-imidazoline ring was investigated. This protocol was also suitable for the synthesis of 2-imidazoles in relatively large scale. (C) 2012 Elsevier Ltd. All rights reserved.