Pinacolborane Chemical Properties

Boiling point:

42-43 °C50 mm Hg(lit.)

Density 

0.882 g/mL at 25 °C(lit.)

vapor pressure 

29-119.9hPa at 20-50℃

refractive index 

n20/D 1.396(lit.)

Flash point:

41 °F

storage temp. 

2-8°C

solubility 

Miscible with ether, dichloromethane, tetrahydrofuran and organic solvents.

form 

Liquid

Specific Gravity

0.882

color 

Clear colorless to light yellow

Sensitive 

Air Sensitive

BRN 

7802871

Stability:

Air Sensitive, Hygroscopic, Moisture Sensitive

InChI

InChI=1S/C6H13BO2/c1-5(2)6(3,4)9-7-8-5/h7H,1-4H3

InChIKey

UCFSYHMCKWNKAH-UHFFFAOYSA-N

SMILES

O1C(C)(C)C(C)(C)OB1

CAS DataBase Reference

25015-63-8(CAS DataBase Reference)

Safety Information

Hazard Codes 

F,Xi,Xn

Risk Statements 

11-15-36/37/38-36/37-19-40

Safety Statements 

16-43-8-37/39-26-33-29-36/37

RIDADR 

UN 3398 4.3/PG 2

WGK Germany 

3

Hazard Note 

Highly Flammable/Keep Cold/Air Sensitive

HazardClass 

4.3

PackingGroup 

II

HS Code 

29209090

Storage Class

4.3 - Hazardous materials which set free flammable gases upon contact with water

Hazard Classifications

Flam. Liq. 2
Water-react 2

MSDS

• Language:English Provider:Pinacolborane
• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Pinacolborane Usage And Synthesis

Chemical Properties

Clear colorless liquid

Uses

Pinacolborane is used as a precursor of boronic esters by hydroboration or coupling reactions. It acts as a monofunctional hydroborating agent. It is used in the synthesis of unsymmetrical biaryls through aromatic C-H borylation-cross-coupling sequence. It is involved in the preparation of 4,4,5,5-tetramethyl-2-thiophen-2-yl-[1,3,2]dioxaborolane by reacting with 2-iodo-thiophene. Further, it is used to prepare vinylboronates by palladium-catalyzed coupling with alkenyl triflates and iodides.

Uses

Pinacolborane is used for synthesis of unsymmetrical biaryls via aromatic C-H borylation-cross-coupling sequence.

Synthesis

Pinacol (177 g, 1.5 mol) and CH2Cl2 (1.6 L) were added to a 5 L round bottom flask. Borane dimethyl sulfide (10 M, 159 mL, 0.16 mol) was added to the flask via cannula and the mixture was stirred at 0??C for 4 hours. The reaction mixture was then heated to room temperature overnight with stirring.17 After 17 h, the reaction mixture gave off some gas (hydrogen); however, the reaction was heated and slowly depressurized (760 mm to 200 mm). This process allowed CH2Cl2 (1.3 L) to move away from the reaction. The remaining liquid was transferred to a 500 mL flask through a cannula and the pressure was slowly reduced from atmospheric to 50 mm over 2.5 h. Some initial foaming was observed in the viscous liquid due to continued outgassing. The method provided pinacol borane suitable for subsequent reactions. The yield was 157 g, 81.7%.

Pinacolborane(25015-63-8)Related Product Information

• Bis(pinacolato)diboron
• 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
• Diborane
• METHYLCYCLOPENTADIENE DIMER
• 1,3-Dioxolane
• 1,4-Dioxane
• Borane-tetrahydrofuran complex
• Methoxydiethylborane
• Methyl cyclopentenolone
• Pentaborane
• 4'-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)ACETANILIDE
• METHYL 4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)BENZOATE
• 4-Carboxylphenylboronic acid pinacol ester
• Allylboronic acid pinacol ester
• (2-BROMOMETHYLPHENYL)BORONIC ACID, PINACOL ESTER
• 3-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)PHENOL
• 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)aniline
• 2-Furanboronic acid pinacol ester