Allyl bromide → Ethyl 2-allyl-2-(diphenylmethyleneamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate

HRID 579488Notes

Reaction equation

HRID 579488 reaction equation
[C:1]1([C:7](=[N:14][CH:15]([CH2:21][CH2:22][CH2:23][CH2:24][B:25]2[O:29][C:28]([CH3:31])([CH3:30])[C:27]([CH3:33])([CH3:32])[O:26]2)[C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH2:34]1[CH2:38]OC[CH2:35]1.C[Si]([N-][Si](C)(C)C)(C)C.[Li+].C(Br)C=C>C(OCC)(=O)C>[CH2:38]([C:15]([N:14]=[C:7]([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1)([CH2:21][CH2:22][CH2:23][CH2:24][B:25]1[O:26][C:27]([CH3:32])([CH3:33])[C:28]([CH3:31])([CH3:30])[O:29]1)[C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH:34]=[CH2:35]

Participants

6

Reactant 4

HCID 7841Allyl bromideHCID 8028TetrahydrofuranHCID 2733832Lithium HexamethyldisilazideHCID 86663712Ethyl 2-(diphenylmethyleneamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate

Product 1

HCID 86663713Ethyl 2-allyl-2-(diphenylmethyleneamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoateYield 59%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of ethyl 2-(diphenylmethyleneamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate (2.79 g, 6.21 mmol) in freshly distilled (THF 15 mL, 0.4 M) was cooled to −78° C. and treated with lithium bis(trimethylsilyl)amide (6.8 mL, 1.0 M in THF). After stirring for 10 min allyl bromide (2.25 g, 18.6 mmol) was added the reaction was warmed to room temperature and stirred for 16 h. After being complete by TLC, the reaction mixture was cooled to 0° C., diluted with ethyl acetate and washed successively with saturated aqueous NaHCO3 and saturated aqueous NaCl, dried over MgSO4, filtered and concentrated. Purification by MPLC (1-20% ethyl acetate in heptane with 0.5% triethylamine over 6 CV) gave ethyl 2-allyl-2-(diphenylmethyleneamino)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanoate as a colorless oil (1.81 g, 59%). Rf 0.52 (30% ethyl acetate in heptane); 1H NMR (CDCl3, 300 MHz) δ 7.58-7.53 (m, 2H), 7.39-7.22 (m, 6H), 7.16-7.12 (m, 2H), 5.89-5.74 (m, 1H), 5.07 (dd, J1=15.3 Hz, J2=2.1 Hz, 1H), 5.05 (dd, J1=8.7 Hz, J2=2.1 Hz, 1H), 3.70 (q, J=7.5 Hz, 1Hdiasterotopic), 3.69 (q, J=7.2 Hz, 1Hdiasterotopic), 2.70 (dd, J1=7.2 Hz, J2=1.2 Hz, 2H), 1.92-1.83 (m, 2H), 1.44-1.35 (m, 2H), 1.35-1.23 (m, 2H), 1.19 (s, 12H), 1.10 (t, J=7.2 Hz, 3H), 0.78 (t, J=6.6 Hz, 2H).

Workup

  1. additionwas added the reaction
  2. temperaturewas warmed to room temperature
  3. temperaturethe reaction mixture was cooled to 0° C.
  4. washwashed successively with saturated aqueous NaHCO3 and saturated aqueous NaCl
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customPurification by MPLC (1-20% ethyl acetate in heptane with 0.5% triethylamine over 6 CV)

Sources & evidence

ORD record
ord-689c613a8a82452e8842c738e0d8dda3
Source dataset
uspto-grants-2015_05
Patent number
US09040703B2

Reaction notes

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