✦ LIBER ✦

Enthalpy- and/or entropy-controlled asymmetric oxidation: stereocontrolling factors in Mn–salen-catalyzed oxidation

✍ Scribed by Tomohiro Nishida; Akio Miyafuji; Yoshio N Ito; Tsutomu Katsuki

Publisher: Elsevier Science
Year: 2000
Tongue: French
Weight: 351 KB
Volume: 41
Category: Article
ISSN: 0040-4039
DOI: 10.1016/s0040-4039(00)01210-7

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✦ Synopsis

The degree of enantioselection by second-generation Mn±salen complexes was found to depend upon the conformation of their ligand and substrate nucleophilicity. Oxidation of usual ole®ns was better eected by using (R,S)-Mn±salen complexes as catalysts, while that of more nucleophilic ones was achieved by using (R,R)-Mn±salen complexes. This phenomenon was explained by analyzing the enthalpy and entropy factors of the reactions.