13826-27-2Relevant articles and documents
A short synthesis of tetraalkoxydiborane(4) reagents
Anastasi, Natia R.,Waltz, Karen M.,Weerakoon, Wimali L.,Hartwig, John F.
, p. 365 - 369 (2003)
The synthesis of a series of bis(catecholato)diborane(4) compounds, B2(1,2-O2C6H4)2, B2-(1,2-O2C6H3Me-4)2, B2(1,2-O2C6H2Me2-3,5) 2, B2[1,2-O2C6H3But-4)] 2, and B2[1,2-O2C6H2But2 -3,5]2, is reported. The compounds have been synthesized by reaction of 1% sodium/mercury amalgam with the corresponding halocatecholboranes, which are cleanly formed from the reaction of BCl3 or BBr3 and catechol. Combining these two steps in one pot, B2[1,2-O2C6H3But-4)] 2 was prepared from BCl3 and 4-tert-butylcatechol, and B2[1,2-O2C6H2But2 -3,5]2 was prepared from 3,5-di-tert-butylcatechol and BBr3 on a multigram scale. Bis-(pinacolato)diborane(4) was not formed from reaction of chloropinacolborane and Na/Hg, but it was formed by in situ addition of pinacol to either B2[1,2-O2C6H3But-4)] 2 or B2[1,2-O2C6H2But2 -3,5]2. Cyclic voltammetry indicated that the reduction potentials of the chloro-catecholborane reactant and of the bis(catecholato)diborane(4) product are similar. These similar potentials make selective reduction of haloborane difficult and thus far unique to sodium-mercury amalgam.
Transition-metal-catalyzed synthesis of diboranes(4)
Braunschweig, Holger,Guethlein, Frank
, p. 12613 - 12616 (2011)
The diboranes(4) bis(catecholato)diborane (B2Cat2) and bis(pinacolato)diborane (B2Pin2) are important precursors for organoboronic esters, which are versatile reagents for the formation of carbon-carbon bonds. A new catalytic synthesis for these compounds starts from catecholborane or pinacolborane and gives the dehydrocoupling products B2Cat2 and B2Pin2 with turnover numbers of up to 11 600 (see scheme). Copyright
Metal-Free Direct Deoxygenative Borylation of Aldehydes and Ketones
Huang, Chia-Yu,Li, Chao-Jun,Li, Jianbin,Qiu, Zihang,Wang, Haining
supporting information, p. 13011 - 13020 (2020/09/01)
Direct conversion of aldehydes and ketones into alkylboronic esters via deoxygenative borylation represents an unknown yet highly desirable transformation. Herein, we present a one-step and metal-free method for carbonyl deoxy-borylation under mild conditions. A wide range of aromatic aldehydes and ketones are tolerated and successfully converted into the corresponding benzylboronates. By the same deoxygenation manifold with aliphatic aldehydes and ketones, we also enable a concise synthesis of 1,1,2-tris(boronates), a family of compounds that currently lack efficient synthetic methods. Given its simplicity and versatility, we expect that this novel borylation approach could show great promise in organoboron synthesis and inspire more carbonyl deoxygenative transformations in both academic and industrial settings.
Transition-metal catalyzed synthesis of diboranes(4)
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Paragraph 0057, (2013/03/26)
Disclosed is a process for the preparation of a diborane(4) comprising the step of coupling boranes via homogeneous or heterogeneous catalysis in the presence of a catalyst comprising a transition metal selected from Ti, Zr, Hf, Rh, Ir, Ni, Pd and Pt.
