We describe a cerium‐catalyzed aerobic oxidative ringexpansion for the expedient construction of synthetically challenging macrolactones under visible‐light conditions. Cyanoanthracene has been employed as co‐catalyst to accelerate the turnover of the cerium cycle leading to a fast conversion within 20 min of irradiation. Taking advantage of the high efficiency and operationally simple conditions
Synthesis and Structure‐Activity Relationship Studies of C(13)‐Desmethylene‐(−)‐Zampanolide Analogs
作者:Tobias M. Brütsch、Etienne Cotter、Daniel Lucena‐Agell、Mariano Redondo‐Horcajo、Carolina Davies、Bernhard Pfeiffer、Sandro Pagani、Simone Berardozzi、J. Fernando Díaz、John H. Miller、Karl‐Heinz Altmann
DOI:10.1002/chem.202300703
日期:2023.6.27
Reduced or demethylated variants of a C(13)-desmethylene congener of the marine microtubule stabilizer (−)-zampanolide have been prepared by HWE-based macrocyclization and stereoselective construction of the hemiaminal center in the side chain. While all modifications led to reduced growth inhibitory activity, the 2,3-dihydro and the C(17)-desmethyl variants retained potent antiproliferative activity
σ–π Chelation-controlled chemoselective ring openings of epoxides
作者:Naoki Asao、Taisuke Kasahara、Yoshinori Yamamoto
DOI:10.1016/s0040-4039(01)01669-0
日期:2001.10
The chemoselective ring opening of alkynyl epoxides in the co-existence of the corresponding alkyl epoxides is achieved in the Me3Al mediated reaction with alkynyllithium reagents. The observed interesting chemoselectivity is most probably a reflection of bidentate complexation of the Lewis acid to an n-electron of an oxygen atom of the epoxide and pi -electrons of the C C triple bond. (C) 2001 Elsevier Science Ltd. All rights reserved.