tert-Butyl hydroperoxide → 1H-Indene-2-carboxylic acid, 5-chloro-2,3-dihydro-2-hydroxy-1-oxo-, methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A chiral zirconium complex was prepared by rapidly stirring (forming a vortex) a mixture of zirconium(IV) acetylacetonate (43.5 mg, 0.089 mmol) and 2,2′-[[(1S,2S)-1,2-diphenyl-1,2-ethanediyl]bis(iminomethylene)]bis[6-(1,1-dimethylethyl)-phenol] (Formula IIIb wherein R6 is H, 0.096 g, 0.18 mmol) in toluene (1.00 mL) at 50° C. for one hour. The resulting solution was evaporated to dryness in vacuo, then a solution of methyl 5-chloro-2,3-dihydro-1-oxo-1H-indene-2-carboxylate (0.500 g, 2.23 mmol) (Formula IIa wherein R1 is OCH3 and R4 is Cl) in toluene (2.00 mL) was added. The reaction mixture was heated to 65° C., and then an aqueous solution of tert-butyl hydroperoxide (70%, 0.316 g, 0.340 mL, 2.46 mmol) was added. After 3.5 hours at 65° C., the reaction was quenched by adding an acetonitrile solution (7.00 mL) containing biphenyl (0.125 g) as an HPLC internal standard and cooling to ambient temperature. Analysis by quantitative and chiral HPLC showed 100% conversion of methyl 5-chloro-2,3-dihydro-1-oxo-1H-indene-2-carboxylate, forming methyl 5-chloro-2,3-dihydro-2-hydroxy-1-oxo-1H-indene-2-carboxylate in 85% yield (85% chemoselectivity) and 94% enantiomeric excess of the S-enantiomer.

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