Vinyltrimethylsilane → 4-Bromo-2-methyl-1-vinylbenzene

HRID 735575

Reaction equation

HRID 735575 reaction equation
[F-].[K+].[Br:3][C:4]1[CH:5]=[CH:6][C:7](I)=[C:8]([CH3:10])[CH:9]=1.C[Si](C)(C)[CH:14]=[CH2:15]>[N+](CCCC)(CCCC)(CCCC)CCCC.[Cl-].C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].C1(C)C=CC=CC=1>[Br:3][C:4]1[CH:5]=[CH:6][C:7]([CH:14]=[CH2:15])=[C:8]([CH3:10])[CH:9]=1

Participants

7

Reactant 3

HCID 79102VinyltrimethylsilaneHCID 522689Potassium FluorideHCID 27246015-Bromo-2-iodotoluene

Product 1

HCID 225986564-Bromo-2-methyl-1-vinylbenzeneYield 76.1%

Reagents, catalysts & solvents 3

HCID 70681Tetrabutylammonium ChlorideCatalystHCID 6505921(1E,4E)-1,5-diphenylpenta-1,4-dien-3-one; palladiumCatalystHCID 1140TolueneSolvent

Procedure

KF (870 mg, 15 mmol), n-Bu4NCl (2.77 g, 10 mmol), Pd(dba)2 (145 mg, 0.25 mmol), molecular sieves (4 Ang, 200 mg, activated balls), 5-bromo-2-iodo-1-methylbenzene (1.49 g, 5 mmol), trimethyl(vinyl)silane (2.7 mL, 20 mmol), and toluene (10 mL) were added to a pressure vessel and sparged with Ar. The vial was sealed and microwaved at 170° C. for 30 min. The mixture was cooled to ambient temperature, diluted with hexanes, filtered and concentrated. The crude oil was purified by flash chromatography (100% hexanes) to yield 30A (750 mg, 76%) as a clear oil. 1H NMR (400 MHz, CDCl3) δ ppm 2.31 (s, 3 H) 5.31 (dd, J=10.99, 1.10 Hz, 1 H) 5.62 (dd, J=17.59, 1.10 Hz, 1 H) 6.84 (dd, J=17.04, 10.99 Hz, 1 H) 7.26-7.35 (m, 3 H).

Workup

  1. customsparged with Ar
  2. customThe vial was sealed
  3. custommicrowaved at 170° C. for 30 min
  4. additiondiluted with hexanes
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe crude oil was purified by flash chromatography (100% hexanes)

Sources & evidence

ORD record
ord-666cf4473f3d4295b9af41df5521200b
Source dataset
uspto-grants-2009_09
Patent number
US07592331B2

Linked notes

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