1,3-Benzodioxole → 5-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-2H-1,3-benzodioxole

HRID 1244880

Reaction equation

HRID 1244880 reaction equation
[B]1[O:5][C:4]([CH3:7])([CH3:6])[C:3]([CH3:9])([CH3:8])[O:2]1.I[C:11]1[CH:16]=[CH:15][C:14]2[O:17][CH2:18][O:19][C:13]=2[CH:12]=1.O1C2C=CC=CC=2OC1.C1([B:35](O)O)C=CC=CC=1>C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2].C(N(CC)CC)C.O1CCOCC1.C(Cl)Cl>[CH3:8][C:3]1([CH3:9])[C:4]([CH3:7])([CH3:6])[O:5][B:35]([C:11]2[CH:16]=[CH:15][C:14]3[O:17][CH2:18][O:19][C:13]=3[CH:12]=2)[O:2]1

Participants

9

Reactant 4

HCID 92291,3-Benzodioxole2×HCID 66827Phenylboronic Acid2×HCID 1386201-Iodo-3,4-methylenedioxybenzeneHCID 6364989Pinacolborane

Product 1

HCID 27605895-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-2H-1,3-benzodioxole

Reagents, catalysts & solvents 4

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 6344DichloromethaneSolventHCID 8471TriethylamineSolvent2×HCID 312751,4-DioxaneSolvent

Conditions

Temperature
80 °C

Procedure

To 25.1 mg PdCl2(dppf).CH2Cl2 in a reaction tube under nitrogen were added 4 ml dioxane, 0.42 ml (3 mmol) triethylamine, 0.16 ml (1.1 mmol) pinacolborane and 256 mg (1.03 mmol) 1-iodo-3,4-methylenedioxybenzene. The reaction solution was warmed to 80° C., with stirring, for 16 h in an oil bath. An aliquot (ca. 0.25 ml) of the reaction solution was removed, extracted into ethyl acetate and washed several times with water and brine solution and analysed by gc (fid detector, SGE HT5 capillary column). Hydrogen evolution was observed on the initial contact of the reaction sample with water, indicative that excess pinacolborane was present at the completion of the reaction even though only 1.1 equivalents had been used. Besides the 1,3-benzodioxole (10% of gc peak area) and pinacol ester of phenylboronic acid (7%), the only other product peak in the gc (area of 81%) was that due to the desired arylboronic acid pinacol ester. In a parallel reaction in which the only change was a reduction in the amount of triethylamine used, from 3.0 equivalents to 1.0 equivalents, the product distribution found was 1,3-benzodioxole (23% of gc peak area), the pinacol ester of phenylboronic acid (6%) and the desired arylboronic acid pinacol ester (peak area 69%).

Workup

  1. customAn aliquot (ca. 0.25 ml) of the reaction solution was removed
  2. extractionextracted into ethyl acetate
  3. washwashed several times with water and brine solution
  4. customindicative that excess pinacolborane was present at the completion of the reaction even though only 1.1 equivalents
  5. customIn a parallel reaction in which the only change

Sources & evidence

ORD record
ord-e130e089ed3e4e999520951cc0469a2b
Source dataset
uspto-grants-2006_10
Patent number
US07122694B2

Linked notes

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