Benzcatechinborane → (S)-ethyl 2-(6-bromo-3-methyl-1-(trifluoromethylsulfonyloxy)naphthalen-2-yl)-2-hydroxyacetate

HRID 926184Notes

Reaction equation

HRID 926184 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[C:8]([O:12][S:13]([C:16]([F:19])([F:18])[F:17])(=[O:15])=[O:14])=[C:7]([C:20](=[O:26])[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:6]([CH3:27])=[CH:5]2.B1(C)OC(C2C=CC=CC=2)(C2C=CC=CC=2)[C@@H]2N1CCC2.[B]1OC2C(=CC=CC=2)O1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[C:8]([O:12][S:13]([C:16]([F:17])([F:19])[F:18])(=[O:15])=[O:14])=[C:7]([C@H:20]([OH:26])[C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:6]([CH3:27])=[CH:5]2

Participants

5

Reactant 3

HCID 6327445BenzcatechinboraneHCID 9838490(R)-2-Methyl-CBS-oxazaborolidineHCID 89676645Ethyl 2-(6-bromo-3-methyl-1-(trifluoromethylsulfonyloxy)naphthalen-2-yl)-2-oxoacetate

Product 1

HCID 89681790(S)-ethyl 2-(6-bromo-3-methyl-1-(trifluoromethylsulfonyloxy)naphthalen-2-yl)-2-hydroxyacetate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

To a solution of ethyl 2-(6-bromo-3-methyl-1-(trifluoromethylsulfonyloxy)naphthalen-2-yl)-2-oxoacetate (2 g, 4.26 mmol) and (R)-2-methyl-CBS-oxazaborolidine (0.236 g, 0.85 mmol) in anhydrous toluene at −40° C. was added a solution of catecholborane (0.615 mL, 5.79 mmol) in toluene (10 mL) over 40 minutes. The reaction mixture was stirred for 1 hour and quenched with sodium carbonate solution, diluted with ethyl acetate and stirred vigorously for 20 minutes at −20° C., then at room temperature for 45 minutes. The aqueous layer was removed and the organic layer was washed with sodium carbonate solution (4×), saturated ammonium chloride solution, dried (MgSO4), filtered, concentrated and purified by flash column chromatography (silica gel, 0 to 20% ethyl acetate/hexanes) to give the desired compound.

Workup

  1. customquenched with sodium carbonate solution
  2. additiondiluted with ethyl acetate
  3. stirringstirred vigorously for 20 minutes at −20° C.
  4. waitat room temperature for 45 minutes
  5. customThe aqueous layer was removed
  6. washthe organic layer was washed with sodium carbonate solution (4×), saturated ammonium chloride solution
  7. dry with materialdried (MgSO4)
  8. filtrationfiltered
  9. concentrationconcentrated
  10. custompurified by flash column chromatography (silica gel, 0 to 20% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-bd990848a83f4e13b31118bdeec58600
Source dataset
uspto-grants-2016_03
Patent number
US09284323B2

Reaction notes

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