Reaction #1450434

Reaction equation

acetonitrile

trans-2-(4-chlorophenyl)vinylboronic acid

3-bromo-4-formylthiophene

K3PO4

→

4-[2-(4-chlorophenyl)-vinyl]-thiophene-3-carbaldehyde

Yield 54.8%

Solvents

water

Conditions

Workup

1. 1
   OtherThe vial was purged with N2
2. 2
   Othercapped tightly
3. 3
   Other(aluminum multi-reaction block)
4. 4
   Extractionextracted with EtOAc (3×50 mL)
5. 5
   WashThe combined extracts were washed with brine
6. 6
   Dryingdried over Na2SO4
7. 7
   Filtrationfiltered
8. 8
   Concentrationconcentrated
9. 9
   OtherPurification by flash chromatography (Isco CombiFlash) 0-10% EtOAc in heptane

Procedure

To a 40-mL scintillation vial containing trans-2-(4-chlorophenyl)vinylboronic acid (0.42 g, 2.30 mmol), 3-bromo-4-formylthiophene (0.40 g, 2.09 mmol), K3PO4 (0.490 g, 2.30 mmol), TPP (22 mg, 0.08 mmol, 4 mol %), Pd(OAc)2 (4.7 mg, 0.02 mmol, 1 mol %) and a stir-bar, was added acetonitrile (2.5 mL). The vial was purged with N2, capped tightly and heated at 94° C. (aluminum multi-reaction block) while vigorously stirred for 32 h. The reaction was diluted with water and extracted with EtOAc (3×50 mL). The combined extracts were washed with brine, dried over Na2SO4, filtered and concentrated. Purification by flash chromatography (Isco CombiFlash) 0-10% EtOAc in heptane afforded the desired 4-[2-(4-chlorophenyl)-vinyl]-thiophene-3-carbaldehyde (285 mg, 54%). 1H NMR (400 MHz, CDCl3) δ ppm 6.99 (d, J=16.38 Hz, 1H), 7.31-7.36 (m, 2H), 7.45-7.49 (m, 2H), 7.50 (d, J=3.20 Hz, 1H), 7.76 (dd, J=16.34, 0.78 Hz, 1H), 8.13 (d, J=3.20 Hz, 1H), 10.07 (d, J=0.82 Hz, 1H).

Source