Halodeboronation of organotrifluoroborates using tetrabutylammonium tribromide or cesium triiodide

Haloboration: scope, mechanism and utility

“… 25 Other functionalisation includes formation of R–B(dan) (dan = 1,8-diaminonaphthalen- N , N ′-diyl), 74 R–B(MIDA) complexes (MIDA = N -Methyliminodiacetate), 75 or R–BF 3 K salts. 66,76 As expected, these classes of compounds are versatile reagents in transition-metal catalysed transformations such as Suzuki–Miyaura cross-coupling or Rh-catalysed [2 + 2 + 2] cycloadditions owing to their ambiphilic nature (electrophilic C–X/nucleophilic C–B). 39,77–80 …”

“… 63–65 1,2-Dihaloalkenes can also be accessed from terminal alkynes if post haloboration the boron moiety is transformed into an R–BF 3 K salt and then treated with an electrophilic halogenating agent. 66 Suzuki et al first employed vinylBBr 2 derivative 56 in a one-pot two-steps Negishi/Suzuki–Miyaura cross-coupling sequence to access 1,2-disubstituted alkenes ( 57 ) selectively ( Scheme 21b ). 67,68 Although yields were good, the β-bromoalkenyl dibromoboranes 56 were found to be prone to retro-haloboration in the presence of Pd complexes, making further derivatisation to boronic esters expedient to lower the Lewis acidity of the B atom.…”

Quantitative Construction of C≡C Bond: Renaissance of Reductive Coupling of Benzotribromides Promoted by Cu/Polyamine

“…The resulting product was analyzed by NMR and GC‐MS and its composition can be obtained. NMR spectra of products obtained from different ligands (Figure ) reveals that 9 mol% of 1,2‐diphenylacetylene ( 2 a ), 77 mol% of cis ‐1,2‐dibromostilbene ( 3 a) and 14 mol% of trans ‐1,2‐dibromostilbene ( 4 a) were obtained when PMDETA (N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine) was used as ligand. 2 a (58 mol%) and 3 a (42 mol%) were found when TPMA (tris[(2‐pyridyl)methyl]amine) was used.…”

Synthetic utility of biomimicking vanadium bromoperoxidase and n-tetrabutylammonium tribromide (TBATB) in organic synthesis

“…Different halogenation methods are available for producing mono-aryl halogenated products. 69,70 Yao et al 71,72 have conducted bromodeboronation reaction successfully with high yields using TBATB as the catalyst. Simpler reaction procedure, easy isolation of the brominated products and applicable to a wide range of substrates such as methoxy, aldehyde, ester, amide, phenol, cyano, and nitro groups are salient features of this reaction.…”