4,4,5,5-Tetramethyl[1,3,2]dioxaborolane → 5-Ethyl-2,2-diphenyl-4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-butyl]-oxazolidine-4-carboxylic acid tert-butyl ester

HRID 579523Notes

Reaction equation

HRID 579523 reaction equation
[C:1]([O:5][C:6]([C:8]1([CH2:27][CH2:28][CH:29]=[CH2:30])[CH:12]([CH2:13][CH3:14])[O:11][C:10]([C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[NH:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH3:31][C:32]1([CH3:39])[C:36]([CH3:38])([CH3:37])[O:35][BH:34][O:33]1>ClCCl.C(OCC)(=O)C.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[Cl-].[Rh]>[C:1]([O:5][C:6]([C:8]1([CH2:27][CH2:28][CH2:29][CH2:30][B:34]2[O:35][C:36]([CH3:38])([CH3:37])[C:32]([CH3:39])([CH3:31])[O:33]2)[CH:12]([CH2:13][CH3:14])[O:11][C:10]([C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=2)([C:21]2[CH:22]=[CH:23][CH:24]=[CH:25][CH:26]=2)[NH:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 2

HCID 27347684,4,5,5-Tetramethyl[1,3,2]dioxaborolaneHCID 668332184-But-3-enyl-5-ethyl-2,2-diphenyl-oxazolidine-4-carboxylic acid tert-butyl ester

Product 1

HCID 668332165-Ethyl-2,2-diphenyl-4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-butyl]-oxazolidine-4-carboxylic acid tert-butyl esterYield 50%

Reagents, catalysts & solvents 3

HCID 84599Chlorotris(triphenylphosphine)rhodium(I)CatalystHCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 4-but-3-enyl-5-ethyl-2,2-diphenyl-oxazolidine-4-carboxylic acid tert-butyl ester (230 mg, 0.56 mmol) in dichloromethane (2 mL, 0.3 M) was added chlorotris (triphenylphosphine)rhodium(I) (60 mg, 0.065 mmol, 10 mol %) at room temperature. After stirring for 30 min, 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (200 μl, 1.3 mmol, 2 eq) was added to the reaction mixture and stirred overnight. After quenching the reaction with water (3 mL), the resulting solution was diluted with ethyl acetate and washed successively with water and saturated aqueous NaCl, dried over MgSO4, filtered and concentrated. Purification by MPLC (1-40% ethyl acetate in heptane) gave 5-Ethyl-2,2-diphenyl-4-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-butyl]-oxazolidine-4-carboxylic acid tert-butyl ester (152 mg, 0.28 mmol, 50%).

Workup

  1. stirringstirred overnight
  2. customAfter quenching
  3. customthe reaction with water (3 mL)
  4. washwashed successively with water and saturated aqueous NaCl
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customPurification by MPLC (1-40% ethyl acetate in heptane)

Sources & evidence

ORD record
ord-d4949da2b35e4e6da5ec75f8c9a42fd6
Source dataset
uspto-grants-2015_05
Patent number
US09040703B2

Reaction notes

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