Catecholborane → (S)-isopropyl 2-(5-bromo-4-(3-isopropylazetidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate

HRID 718383

Reaction equation

HRID 718383 reaction equation
O1C2C=CC=CC=2OB1.[Br:10][C:11]1[C:12]([N:27]2[CH2:30][CH:29]([CH:31]([CH3:33])[CH3:32])[CH2:28]2)=[C:13]([C:19](=[O:26])[C:20]([O:22][CH:23]([CH3:25])[CH3:24])=[O:21])[C:14]([CH3:18])=[N:15][C:16]=1[CH3:17].CB1N2CCC[C@@H]2C(C2C=CC=CC=2)(C2C=CC=CC=2)O1>C1(C)C=CC=CC=1>[Br:10][C:11]1[C:12]([N:27]2[CH2:30][CH:29]([CH:31]([CH3:33])[CH3:32])[CH2:28]2)=[C:13]([C@H:19]([OH:26])[C:20]([O:22][CH:23]([CH3:25])[CH3:24])=[O:21])[C:14]([CH3:18])=[N:15][C:16]=1[CH3:17]

Participants

5

Reactant 3

HCID 67506CatecholboraneHCID 9838490(R)-2-Methyl-CBS-oxazaborolidineHCID 118307786Isopropyl 2-(5-bromo-4-(3-isopropylazetidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate

Product 1

HCID 118307805(S)-isopropyl 2-(5-bromo-4-(3-isopropylazetidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetateYield 71%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
-15 °C

Procedure

The 0.7 mL of benzo[d][1,3,2]dioxaborole (396 mg, 3.3 mmol) was added to a nitrogen purged solution of isopropyl 2-(5-bromo-4-(3-isopropylazetidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate (875 mg, 2.2 mmol) and 0.66 mL of (R)-1-methyl-3,3-diphenylhexahydropyrrolo[1,2-c][1,3,2]oxazaborole (183 mg, 0.66 mmol) in toluene (20 mL) at −60° C. and allowed to warm to −15° C. before being placed in the freezer overnight. The reaction was quenched with 1M Na2CO3 (5 mL), diluted with EtOAc, and stirred for 20 min. The organic layer was washed with brine and dried (MgSO4). The crude product was charged (DCM) to a 80 g ISCO silica gel cartridge and gradient elution (5-35% EtOAc/hexanes) using an Isolera chromatography station gave (S)-isopropyl 2-(5-bromo-4-(3-isopropylazetidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate 621 mg (71%) as a mixture of diastereomers. 1H NMR (500 MHz, DMSO-d6) δ 5.19 (d, J=4.4 Hz, 1H), 4.96-4.92 (m, 1H), 4.50 (t, J=8.1 Hz, 1H), 4.39 (t, J=8.4 Hz, 1H), 4.07 (t, J=7.0 Hz, 1H), 3.97 (t, J=7.3 Hz, 1H), 2.42 (s, 3H), 2.21 (s, 3H), 2.21-2.17 (m, 1H), 1.73-1.67 (m, 1H), 1.17 (d, J=6.2 Hz, 3H), 1.12 (d, J=6.2 Hz, 3H), 0.83 (d, J=6.6 Hz, 6H). UPLC (M+H)=401.3.

Workup

  1. custombefore being placed in the freezer overnight
  2. customThe reaction was quenched with 1M Na2CO3 (5 mL)
  3. additiondiluted with EtOAc
  4. washThe organic layer was washed with brine
  5. dry with materialdried (MgSO4)
  6. additionThe crude product was charged (DCM)
  7. washto a 80 g ISCO silica gel cartridge and gradient elution (5-35% EtOAc/hexanes)

Sources & evidence

ORD record
ord-5a7d88889fcf4e7baddc2a5083805b9a
Source dataset
uspto-grants-2015_11
Patent number
US09193720B2

Linked notes

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