Bis(pinacolato)diboron

Bis(pinacolato)diboron

Names
IUPAC name 4,4,4',4',5,5,5',5'-Octamethyl-2,2'-bi-(1,3,2-dioxaborolane)
Identifiers
CAS Number	73183-34-3 Y
3D model (Jmol)	Interactive image
Abbreviations	B2pin2
ChemSpider	2015334 N
ECHA InfoCard	100.111.245
PubChem	2733548
InChI InChI=1S/C12H24B2O4/c1-9(2)10(3,4)16-13(15-9)14-17-11(5,6)12(7,8)18-14/h1-8H3 N Key: IPWKHHSGDUIRAH-UHFFFAOYSA-N N InChI=1/C12H24B2O4/c1-9(2)10(3,4)16-13(15-9)14-17-11(5,6)12(7,8)18-14/h1-8H3 Key: IPWKHHSGDUIRAH-UHFFFAOYAV
SMILES B1(OC(C(O1)(C)C)(C)C)B2OC(C(O2)(C)C)(C)C
Properties
Chemical formula	C12H24B2O4
Molar mass	253.94 g·mol−1
Melting point	137 to 140 °C (279 to 284 °F; 410 to 413 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Bis(pinacolato)diboron is covalent compound containing two boron atoms and two pinacolato ligands. It has the formula [(CH₃)₄C₂O₂B]₂; the pinacol groups are sometimes abbreviated as "pin", so the structure is sometimes represented as B₂pin₂. It is a colourless solid that is soluble in organic solvents. It is a commercially available reagent for making pinacol boronic esters for organic synthesis. Unlike some other diboron compounds, B₂pin₂ is not moisture-sensative and can be handled in air.^[1]

Preparation and structure

This compound may be prepared by reacting tetrakis(dimethylamino)diboron with pinacol in acidic conditions.^[1] The B-B bond distance is 1.711(6) Å.^[2]

Reactions

The B-B bond adds across alkenes and alkynes to give the 1,2-diborylated alkanes and alkenes. Using various organorhodium or organoiridium catalysts, it can also be installed onto saturated hydrocarbons:^[3]

CH₃(CH₂)₆CH₃ + [pinB]₂ → pinBH + CH₃(CH₂)₇Bpin

References