Formation of epoxides and N-arylaziridines via a simple Mg-Barbier reaction in DMF
作者:Sylvain Oudeyer、Eric Léonel、Jean Paul Paugam、Jean-Yves Nédélec
DOI:10.1016/j.tet.2013.12.016
日期:2014.1
The Mg-activation of benzal bromide 2b in DMF in the presence of carbonyl compounds 1 or imines 4 leads to epoxides 3 and N-arylaziridines 5, respectively, with acceptable isolated yields. It was found that DMF is likely involved in this process to form a nucleophilic intermediate by reaction with a first generated electrophilic carbene. Results obtained in this chemical approach are compared to those
Enantioselective Synthesis of (Thiolan-2-yl)diphenylmethanol and Its Application in Asymmetric, Catalytic Sulfur Ylide-Mediated Epoxidation
作者:Hsin-Yi Wu、Chih-Wei Chang、Rong-Jie Chein
DOI:10.1021/jo400648f
日期:2013.6.7
This work describes an expeditious and efficient preparation of enantiopure (thiolan-2-yl)diphenylmethanol (2) featuring a double nucleophilic substitution and Shi epoxidation as key steps. One of the applications of its benzyl ether derivative to asymmetric sulfur ylide-mediated epoxidation with up to 92% ee (14 examples) was also demonstrated herein.
Generation and Reactions of Oxiranyllithiums by Use of a Flow Microreactor System
作者:Aiichiro Nagaki、Eiji Takizawa、Jun-ichi Yoshida
DOI:10.1002/chem.201000815
日期:2010.12.17
A flowmicroreactorsystem consisting of micromixers and microtubes provides an effective reactor for the generation and reactions of aryloxiranyllithiums without decomposition by virtue of short residence time and efficient temperature control. The deprotonation of styrene oxides with sBuLi can be conducted by using the flowmicroreactorsystem at −78 or −68 °C (whereas much lower temperatures (<−100 °C)
Fluoride ion promoted reactions of .alpha.-halo silanes: synthesis of stilbenes, epoxides, cyclopropanes, benzazepines, and phthalidylisoquinolines
作者:Satinder V. Kessar、Paramjit Singh、Nachhattar Pal Kaur、Usha Chawla、Kalpana Shukla、Punam Aggarwal、D. Venugopal
DOI:10.1021/jo00012a024
日期:1991.6
Reaction of alpha-halo silanes 1 with CsF in DMF affords stilbenes 5. In the presence of added aldehydes, epoxides 6 are obtained, while with electron-deficient olefins the corresponding cyclopropanes 7 are formed. A similar reaction of 1a with iminium compounds 8 in HMPA leads to 2-phenyl-3-benzazepines 12, whereas 1b or 17 furnishes phthalidylisoquinolines 15.
Copper-Catalyzed Aerobic Oxidative Cleavage of C–C Bonds in Epoxides Leading to Aryl Ketones
作者:Lijun Gu、Cheng Jin、Hongtao Zhang、Lizhu Zhang
DOI:10.1021/jo5013898
日期:2014.9.5
A novel copper-catalyzedaerobic synthesis of ketones from epoxides via cleavage of C–C single bonds has been discovered. This reaction constitutes a new transformation from epoxides into ketones.