1300. Bis(pinacolato)diborane

Nomenclature

CAS number: 73183-34-3
4,4,4′,4′,5,5,5′,5′-Octamethyl-2,2′-bi-1,3,2-dioxaborolane; Miyaura's reagent; pinacol diborane; 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-1-yl-4′,4′,5′,5′-tetramethyl-1′,3′,2′-dioxaborolan; B2pin2.
C12H24B2O4; mol wt 253.94.
C 56.76%, H 9.53%, B 8.51%, O 25.20%.

Description and references

Boron source for organic syntheses. Prepn and crystal structure: H. N"oth, Z. Naturforsch. 39b, 1463 (1984). Synthesis: T. Ishiyama et al., Org. Synth. 77, 176 (2000). NMR spectroscopic data: W. Biffar et al., Ber. 113, 333 (1980). First use as boron source in Pt-catalyzed diboration of alkynes: T. Ishiyama et al., J. Am. Chem. Soc. 115, 11018 (1993). Stereospecific synthesis via cross coupling with aromatic amine: C. Malan, C. Morin, J. Org. Chem. 63, 8019 (1998). Rh-catalyzed activation of the C-H bond: Y. Kondo et al., J. Am. Chem. Soc. 124, 1164 (2002). Brief review: X. Liu, Synlett 2003, 2442-2443.

Chemical structure

Properties

Colorless plates, mp 138°. Crystalline form can be handled in air and stored in capped bottle.

Use

As a boron source in Pt-mediated diborations, coupling reactions; in Rh-or Ir-mediated borylations of alkanes and arenes, and in carbenoid chemistry.