Réaction #45472

Équation de réaction

3,3-diethoxy-1-propyne

4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Triethylamine

→

title compound

Rendement 53.0%

2-[(E)-3,3-diethoxy-1-propenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Rendement 53.0%

Solvants

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   Autrethe solvent was removed in vacuo
2. 2
   workup.DISTILLATIONThe residue was distilled at 90° C. at 10 torr
3. 3
   AutreThe residue was purified by column chromatography on neutral alumina using 89:10:1 dichloromethane
4. 4
   AutreThe solvent was removed in vacuo

Mode opératoire

A mixture of 3,3-diethoxy-1-propyne (18.5 g, 0.144 mol), 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (27.6 g, 0.216 mol) and bis(cyclopentadienyl)zirconium chloride hydride (1.9 g, 0.007 mol) in tetrahydrofuran (75 mL) was heated at 50° C. for 2 days. Triethylamine (2 mL) was added and the solvent was removed in vacuo. The residue was distilled at 90° C. at 10 torr. The residue was purified by column chromatography on neutral alumina using 89:10:1 dichloromethane: ethyl acetate: triethylamine as an eluent. The solvent was removed in vacuo to give the title compound (15.9 g, 53%) as a brown oil. 1H NMR (DMSO-d6, 400 MHz) δ 6.48 (dd, 1H), 5.75 (d, 1H), 4.85 (d, 1H), 3.55-3.67 (m, 2H), 3.40-3.52 (m, 2H), 1.22 (s, 12H), 1.17 (t, 6H).

Source