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

Temperatur

55 °C

A chiral zirconium complex was prepared by stirring zirconium(IV) isopropoxide (0.0345 g, 0.089 mmol) with 2,2′-[(1S,2S)-1,2-cyclohexanediylbis(iminomethylene)]bis[4,6-bis(1,1-dimethylethyl)phenol] (Formula IIIc wherein R6 is C(CH3)3, 0.0613 g, 0.11 mmol) in toluene (2 mL) at ambient temperature. After stirring overnight, the homogeneous solution was evaporated to dryness in vacuo, and the residue redissolved in toluene (1.34 g). Methyl 5-chloro-2,3-dihydro-1-oxo-1H-indene-2-carboxylate (0.250 g, 1.11 mmol) (Formula IIa wherein R1 is OCH3 and R4 is Cl) was added to the toluene solution, the solution was heated to 55° C., and then an aqueous solution of tert-butyl hydroperoxide (70%, 0.316 g, 2.46 mmol) was added. After 2 hours at 55° C., the solution was diluted with acetonitrile (11.5 mL) 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 84% yield (84% chemoselectivity) and 84% enantiomeric excess of the 5-enantiomer.

1. customA chiral zirconium complex was prepared
2. customthe homogeneous solution was evaporated to dryness in vacuo
3. dissolutionthe residue redissolved in toluene (1.34 g)
4. waitAfter 2 hours at 55° C.

ORD-Eintrag

ord-ba27f4b2a4a44d42be309c5ae2a02ef3

Quelldatensatz

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07939685B2