Organoborane compounds

Brown HC (1982) Organoboran compounds in organic synthesis. In Wilkinson et al. (eds) Comprehensive organometallic chemistry. Pergamon, Oxford... 

It was also reported that terminally borane-containing POs is available as another macroinitiator to prepare block copolymers (Fig. 4). These polymers were prepared by (1) the metallocene-catalyzed (co)polymerization of olefin(s) with organoborane compounds, for example, 9-borabicyclononane (9-BBN), as chain transfer agents [32], or by (2) the hydroboration of terminally unsaturated polyolefins with BBN [33-36]. 

M) Foster, R., Griasnow, G., Larbig, W., Binger, P. Organoboran compounds by hydro-boration of olefins with alkyl diboranes. Ann. 672, 1 (1964). 

Compared with other organometallics, organoborane compounds are relatively inert to chemical transformations, particularly to ionic reactions, because of the less polar nature of the carbon-boron bond. 

Organoborane compounds, especially boronic acid derivatives, are less reactive and have also been utilized for the trans-selecdwe coupling reaction of l,l-dibromoalkenes.f t Use of UOH and Ba(OH)2 as the activator of boronic acids is important to carry out the selective coupling reaction (Scheme 5). 

Besides the one-pot process described above, the White Reagent catalyzes a chelate-controlled oxidative Heck arylation between a wide range of a-olefins and organoborane compounds in good yields and with excellent regio-and stereoselectivities (Figure 6). Unlike other Heck arylation methods, no Pd-H isomerization is observed under the mild reaction conditions. Aryl boronic acids, styrenylpinacol boronic esters, and aryl potassium trifluoroborates (activated with boric acid) are all compatible with the general reaction conditions. 

Organoborane compounds have also been successfully coupled to alkyl halides. This can be done for alkyl iodides using a simple catalyst system consisting of (Ph3P)4Pd (Scheme 2.97), or, for alkyl bromides, with a nickel catalyst with a bidentate nitrogen ligand (Scheme 2.98). ... 

Organoborane compounds—Congresses. 2. Inorganic compounds—Synthesis— Congresses. 3. Organic compounds—Synthesis—Congresses. 

Organoborane compounds are one of the most commonly used coupling partners for C-C couplings. In 2014, Shi et al. achieved a Pd(ll)-catalyzed selective borylation of methyl C-H bond with O2 as a benign oxidant (Scheme 1.36) [90]. Unambiguously, the produced C-B coupling products possess low reactivity in the presence of palladium catalyst. The direct borylation of unactivated Y-C(sp )-H bond also contribute an efficient access to alcohols, amines, and various functionalized molecules. 

Asymmetric AUylation and Crotylation Controlled by Chiral Reagents The most popular crotylmetal-lic species are organoborate/organoborane compounds. The addition of crotylboronate esters to aldehydes proceeds with high diastereoselectivities (Z)-Crotylboronates give... 

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