Development of Guanidine-Bisurea Bifunctional Organocatalyst Bearing Chirality at the Inner and Outer Sides of the Urea Groups, and Application to Enantioselective α-Hydroxylation of Pyranoindolizine Intermediate for Camptothecin Synthesis

Symmetry

Minami Odagi²  Tatsuya Watanabe²  Kazuo Nagasawa¹ 

[1] Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan;

关键词: α-hydroxylation;    pyranoindolizine;    camptothecin;    organocatalyst;   

DOI  :  10.3390/sym7010043

来源: mdpi

【 摘 要 】

Pyranoindolizine is a tricyclic structure found in various biologically active compounds, such as camptothecin (CPT) and its derivatives. In the case of CPTs, the chirality at the α-position in the α-hydroxyl lactone moiety of pyranoindolizine is important for the antitumor activity. This paper deals with enantioselective oxidation of the α-position in pyranoindolizine lactone, which corresponds at C20 in CPT, with cumene hydroperoxide (CHP) in the presence of newly synthesized guanidine-bisurea bifunctional organocatalysts bearing chirality on both the inner and outer sides of the urea groups.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland