Abstract
The reaction of TpOs VI(N)(OH) 2 ( 1) [Tp = hydrotris(1-pyrazolyl)borate], m-chloroperbenzoic acid ( m-CPBA), and trans-stilbene in C 6H 6 at room temperature gives the diolate complex TpOs VI(N)( trans-O 2C 2H 2Ph 2) ( 2) and m-chlorobenzoic acid ( m-CBA). The trans configuration of the stilbene is retained in the diolate complex as shown in the crystal structure of 2. Complex 2 is hydrolyzed by 2 equivalents of aqueous HCl in CD 2Cl 2 to give rac-hydrobenzoin, the product of cis-dihydroxylation, and TpOs VI(N)Cl 2. cis-Stilbene, styrene, cyclohexene, trans-dimethyl fumarate, trans-methyl cinnamate, and trans-4-dimethylamino-4′-nitrostilbene are also converted to their corresponding free diol products by reaction with 1 and m-CPBA in CD 2Cl 2, and then aqueous HCl. In aqueous HBF 4, oxidation of the water-soluble olefin, 4-styrenesulfonic acid, by 1 is modestly catalytic (15 turnovers in 3 h) with excess PbO 2 as the oxidant. Under non-acidic conditions, the diolate complexes are inert and catalysis is precluded. Mechanistic experiments implicate an oxidizing osmium complex as an intermediate in these reactions.
Sign-in/Register to access full text options 
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 callDisclaimer: 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.
