Bis(pinacolato)diboron

Other Names:

4,4,4',4',5,5,5',5'-Octamethyl-2,2'-bi-(1,3,2-dioxaborolane)

General Information:

Structure:

CAS Number: 73183-34-3

Molecular Weight: 253.94 g/mol

Appearance: Colorless solid

Melting Point: 137-140 C

Bis(pinacolato)diboron is typically used for making pinacol boronate esters. These boronates are generally used subsequently in palladium catalyzed Suzuki couplings. They are also sometimes used in other reactions such as oxidations to form phenols. Pinacol boronate esters are generally easier to handle than boronic acids.

Common Uses:

Reagent for the formation of pinacol boronate esters (typically for subsequent Suzuki reactions)

Procedure excerpt:

. . . the SM (400 mg, 1.41 mmol), bis(pinacolato)diboron (1 g, 3.94 mmol), XPhos (135 mg, 0.28 mmol), Pd(OAc)2 (16 mg, 0.06 mmol), and TEA (570 mg, 5.6 mmol) in dioxane . . .

[full procedure]

Reagent in the two step conversion of aryl halides to aryl alcohols

Procedure excerpt:

To a solution of the SM (2.5 g, 6.3 mmol) in dioxane (30 mL) was added bis(pinacolato)diboron (1.75 g, 6.9 mmol), Pd(dppf)Cl2 (0.46 g, 0.63 mmol), and KOAc (1.85 g, 18.9 mmol). . . .

[full procedure]

References:

1) Patent Reference: WO2010038081, page 129, (33.8 MB)

2) Patent Reference: WO2016023830, page 98, (5.1 MB)

3) Wikipedia: Bis(pinacolato)diboron (link)

4) www.sigmaaldrich.com: Bis(pinacolato)diboron (link)

5) www.tcichemicals.com: Bis(pinacolato)diboron (link)