Bis(Pinacolato)Diboron

Abstract

Bis(pinacolato)diboron reactant: 218 g (4.84 mol) of dimethylamine intermediate: tris(dimethylamino)borane intermediate: bromobis(dimethylamino)borane intermediate: tetrakis(dimethylamino)diboron product: Bis(pinacolato)diboron

Catalysis of the coupling reaction of aryl chlorides with bis(pinacolato)diboron by tricyclohexylphosphine-cyclopalladated ferrocenylimine complexes

“…Similar to the results of the Suzuki reaction and cyanation of aryl chlorides [24][25][26], all the complexes 3a-3h exhibited high activity with catalyst loadings as low as 1 mol% and catalyst 3c was slightly more active (entries 4, [12][13][14][15][16][17][18]. The dimeric complex 2c was almost inactive under the same conditions (entry 19). A significant increase in activity was observed with the addition of PCy 3 as ligand (62%, entry 20).…”

“…Bis(pinacolato)diboron (1) [19,20] is the most widely used diborane reagent, due to its commercial availability and high stability in air, moisture and during chromatography. The coupling reactions of (1) with aryl bromides, iodides or triflates to produce arylboronates have been extensively studied (Scheme 1).…”

Hydroboration, Diboration, Silylboration, and Stannylboration

“…A direct synthesis of tetra(alkoxy)diborons by the Wurtz coupling of (RO) 2 BCl is unsuccessful, but tetra(amido)diborons are available in large quantity by the corresponding reaction of (Me 2 N) 2 BX (X=Cl, Br) with sodium or potassium [100][101][102]. Thus, tetra(alkoxo)diborons (81 [101], 82 [101,102], 83 [103,104], 84 [104] 85 [105] and 86 [106]) are synthesized by the reaction of (Me 2 N) 2 BB(NMe 2 ) 2 with an appropriate alcohol or diol in the presence of 4 equiv. of HCl.…”

Palladium-Catalyzed Borylation of Aryl and Heteroaryl Halides Utilizing Tetrakis(dimethylamino)diboron: One Step Greener

“…16–18 The synthetic sequence for the production of BBA is shared with that of B 2 Pin 2 up to the precursor tetrakis(dimethylamino)diborane [(Me 2 N) 2 BB(NMe 2 ) 2 ]. 19 However, instead of adding pinacol in the last step, (Me 2 N) 2 BB(NMe 2 ) 2 is hydrolyzed with aqueous acid at low temperatures. The product BBA, a white solid, precipitates out of solution and can be filtered off and dried (Scheme 2).…”