Abstract

A series of 20 one chiral epoxides were obtained with excellent yields (up to 99%) and enantioselectivities (up to >99% ee) using hybrid amide-based Cinchona alkaloids. Our method is characterized by low catalyst loading (0.5 mol %) and short reaction times. Moreover, the epoxidation process can be carried out in 10 cycles, without further catalyst addition to the reaction mixture. This methodology significantly enhance the scale of the process using very low catalyst loading.

Highlights

  • A series of 20 one chiral epoxides were obtained with excellent yields (up to 99%) and enantioselectivities (up to >99% ee) using hybrid amide-based Cinchona alkaloids

  • With the growing demand for green and sustainable chemistry, the development of environmentally benign and cheap catalysts remains a great challenge in stereocontrolled organic synthesis.[6]

  • Alternative methods to improving the abilities of Cinchona-based catalysts were presented by the Park[14] and Siva[15] groups, who showed that adding surfactants to reaction mixtures or using ultrasound support increased the enantiomeric excess of products formed

Read more

Summary

Introduction

A series of 20 one chiral epoxides were obtained with excellent yields (up to 99%) and enantioselectivities (up to >99% ee) using hybrid amide-based Cinchona alkaloids. Alternative methods to improving the abilities of Cinchona-based catalysts were presented by the Park[14] and Siva[15] groups, who showed that adding surfactants to reaction mixtures or using ultrasound support increased the enantiomeric excess of products formed. We began the present study with epoxidation of model Echalcone S1 using cinchonidine-based catalyst C1, leading to product P1 with high yield (91%), but low enantioselectivity (29% ee), as shown in Scheme 1.

Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.