Isopropenylboronic acid pinacol ester

Description

Isopropenylboronic acid pinacol ester is a versatile ester reagent used for palladium-catalyzed Suzuki-Miyaura cross-coupling processes, inverse-electron-demand Diels-Alder reaction, Simmons-Smith cyclopropanation reaction, polyene cyclization, stereoselective aldol reactions, Grubbs cross-metathesis reaction, intramolecular Suzuki-Miyaura reaction, Stereoselective cross-metathesis, dipolar cycloaddition, iodosulfonylation, asymmetric conjugate addition and intramolecular hydroacylation and preparation of various therapeutic kinase and enzymatic inhibitors¹. It can be used as an intermediate in the synthesis of variety of cyclic and acyclic organic compounds. It is also shown that the α-Substituted Allyl/Croty of this compound can be used for highly Diastereoand Enantioselective allylboration of aldehydes².

Sources

1. https://www.sigmaaldrich.com/catalog/product/aldrich/663212?lang=en&region=US
2. https://www.trc-canada.com/product-detail/?I821825

Uses

suzuki reaction

Uses

Isopropenylboronic Acid Pinacol Ester, can be used as an intermediate in the synthesis of variety of cyclic and acyclic organic compounds. It is also shown that the α-Substituted Allyl/Croty of this compound can be used for highly Diastereo- and Enantioselective allylboration of aldehydes.

Uses

Reagent used for

• Palladium-catalyzed Suzuki-Miyaura cross-coupling reactions
• Inverse-electron-demand Diels-Alder reaction
• Simmons-Smith Cyclopropanation Reaction
• Polyene cyclization
• Stereoselective aldol reactions
• Grubbs cross-metathesis reaction
• Intramolecular Suzuki-Miyaura reaction
• Stereoselective cross-metathesis
• Dipolar cycloaddition
• Iodosulfonylation
• Asymmetric conjugate addition and intramolecular hydroacylation

Synthesis

76-09-5

557-93-7

28049-80-1

126726-62-3

General procedure for the synthesis of isopropenylboronic acid pinacol esters from pinacol, 2-bromopropene and compound (CAS:28049-80-1): 2-bromopropene (89.58 g, 0.741 mol) was dissolved in 750 mL of tetrahydrofuran, and slowly added dropwise from -10 °C to 0 °C with a mixture of bis(diisopropylamino)boron chloride (183 g, 0.74 mol) and lithium metal (10.4 g, 1.5 mol) mixture followed by 110 mL of tetrahydrofuran under strictly controlled reaction conditions. After the dropwise addition, the reaction was maintained at this temperature for 1 h. Then the temperature was raised to 25 °C and the reaction was continued for 5 h. The reaction was completed with the addition of pinacol. Upon completion of the reaction, pinacol (98.8 g), 2,6-di-tert-butyl-4-methylphenol (4.58 g) and 120 mL of tetrahydrofuran were added and the reaction mixture was heated to reflux. Purification by distillation under reduced pressure afforded 82.1 g of colorless transparent liquid isopropenylboronic acid pinacol ester in 66% yield and 99.7% GC purity. Finally, 2,6-di-tert-butyl-4-methylphenol (0.45 g) was added as a stabilizer for long-term storage.

References

[1] Patent: CN105503923, 2016, A. Location in patent: Paragraph 0018