Boronic dihalides

Boron subhalides are binary compounds of boron and the halogens, where the atomic ratio of halogen to boron is less than 3. The boron monohalides, BC1, [20583-55-5], bromoborane(l) [19961-29-6], BBr, and iodoborane(l) [13842-56-3], BI, are unstable species that have been observed spectroscopically when the respective trihalides were subjected to a discharge (5). Boron dihalide radicals have been studied, and structural and thermochemical data for these species ( BX2) have been deduced (5). 

Transmetallation from 1,8-dilithionaphthalene and/or [Mg(l,8-naphthalenediyl)]4 to a range of boron dihalide and transition metal dihalide complexes affords 1,8-naphthalenediyl complexes, which incorporate an embedded metal-lacyclobutene moiety (Equation 52) (Li/B <1994AGE1247>, Li/Zr <1994CB1851>, Li/Pt <2005JA13494>, Mg/ Ti, Rh, Ir, Pt <1994CB1851 . 

BX3 (X =s F, Cl, or Br) and AICI3 are transformed by MeaSiN3 in CH2CI2 or ether into trimeric boron dihalide azide or into monomeric aluminium dichloride azide (in CH2CI2) or polymeric aluminium chloride diazide. In the boron compounds, i.r. spectra are consistent with the presence of bridging azido-groups, i.e. the structure is (68). 

Aryl boron dihalides, ArBX2 (X=halide) 1270-1215 7.87-8.23 s B-C str, isotopic splitting present... 

Boron dihalides (in boron trihalides) 1030-950 9.71-10.53 s asym B-CI str, isotopic splitting present (for BCI3,... 

The reaction of cobaltocene with organoboron dihalides RBX2 (R = Me, Ph and X = Cl, Br mainly) and boron trihalides (BC13, BBr3) leads essentially to three types of (boratabenzene) cobalt complexes, 19,20, and 21 (7,57). CoCp2 plays a dual role in part it acts as a reductant, in part it... 

Between 1965 and 1969, there were rapid developments in the use of other high temperature species, particularly the silicon dihalides (22-23). boron monofluoride (24), boron atoms (25). silicon atoms (26), and alkali metal atoms (27-28). in reactions at liquid nitrogen temperatures. Clearly this experimental method had to be applied to... 

When the metallic additive to the intermediate 374 was zinc dihalide (or another Lewis acid, such as aluminum trichloride, iron trichloride or boron trifluoride), a conjugate addition to electrophilic olefins affords 381 . In the case of the lithium-zinc transmetallation, a palladium-catalyzed Negishi cross-coupling reaction with aryl bromides or iodides allowed the preparation of arylated componnds 384 ° in 26-77% yield. In addition, a Sn2 allylation of the mentioned zinc intermediates with reagents of type R CH=CHCH(R )X (X = chlorine, bromine) gave the corresponding compounds 385 in 52-68% yield. ... 

A new type of approach to thiocrown ether synthesis involving a [2 + 2] coupling of a>-dithiol and w-dihalide units in the presence of a boron aluminium alkoxide couple has been described [27]. 

Dihalides with two different halogens Boron tribromide, 43 Diols and polyols... 

Diorgano tellurium dihalides form complexes with iodine and interhalogen compounds organic compounds with N, P, O, S, and Se donor atoms boron, aluminum, and gallium trihalides antimony pentachloride and mercury(II) halides. 

Dimethyl tellurium dibromide and boron tribromide formed a thermally unstable 2 1 adduct4. Calorimetric titrations indicated that 1 1 complexes are formed between diphenyl tellurium dihalides and aluminum tribromide or gallium trichloride5 6. 

Dialkyl ether adducts are typical of many boron trihalide adduct systems in that the BF3 adducts tend to be stable, whereas the BC13, BBr3, and BI3 adducts become successively more reactive, decomposing to alkyl halide and alkoxyboron dihalide (60,120). This in-... 

One of the most intensely studied boracychc compound is the borabenzene ligand synthesized by Her-berich and coworkers. Bis- and monoborabenzene cobalt sandwich complexes were first obtained by treating cobaltocene with boron trihalides BX3 (R = Cl, Br) or alkyl/arylboron dihalides (R = alkyl, aryl) as outlined in... 

When 18 is treated with acetone, boronic ester 20 with a cyclooctatriene structure is cleanly obtained indicating the valence tautomerism between 18 and 19. In fact, 19 appears to be the kinetic product in the borylation of lithium or potassium cyclononatetraenide with alkylboron dihalides which rearranges quickly to 18 due to the comparatively high thermodynamic stability of the latter.1819 Acetaldehyde,... 

A novel approach to derivatives of a boron heterocycle isoelectronic to benzene was reported in the reaction of phenylboron dihalide with bis-(cyclopentadienyl)cobalt followed by reaction with tin tetrahromide ... 

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