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1//-Boroles, reactions

A particularly interesting reaction (and one of considerable commercial value in the BOROL process for the in situ bleaching of wood pulp) is the production of dithionite, S204 , from SO2 ... [Pg.154]

Reaction of l-(dimethylamino)-2,5-dihydro-2,5-diphenyl-l//-borole with diisopropylaminolithium and then TMEDA gives 293 [90AG(E)317 95JOM (502)67]. [Pg.169]

The most satisfactory route to the synthesis of the ri -borole complexes is the reaction of dihydroboroles (2-borolenes and 3-borolenes) with metal carbonyls. An alternative method of synthesis includes formation of the borole adducts with ammonia, 320 (R = Me, Ph) [87JOM(336)29]. Thermal reaction of 320 (R = Me, Ph) with M(C0)6 (M = Cr, Mo, W) gives 321 (M = Cr, R = Me, Ph M = Mo, W, R = Ph). There are data in favor of the Tr-electron delocalization over the borole... [Pg.171]

The triple-decked Tj -CpFe(PhBC4H3Et)FeCp-T7 complex is formed from 1-phenyl-4,5-dihydroborepine and [T) -CpFe(CO)2l2 by thermal reaction the boraben-zene derivative 77 -CpFe(PhBC5H4Me) also forms. With Mn2(CO), l-phenyl-4,5-dihydroborepine yields the triple-decker complex (CO)3Mn(PhBC4H3Et)Mn(CO)3. The borole complexes described so far are available using stable boroles as reactants. But borole molecules can also be generated from precursers in the course of complexation. [Pg.69]

The reaction of 2- and 3-borolenes C4H6BR (R = Ph, Me, C H, OMe) with Co, Fe and Mn carbonyls leads, under dehydrogenation of the borolenes, to i7 -borole complexes. 2-Borolene and 3-borolene also react with Mn2(CO), at 160°C to a red-brown triple-decked complex ... [Pg.69]

Dihydro-lH-l,5,2-azasilaboroles derive from the 2,5-dihydro-lH-l,2-aza-boroles ( 6.5.3.3) by substitution of the carbon neighboring N by a silicon atom. They may act as four-electron donors using electron density from the C=C double bond and the N atom. The B atom behaves as an acceptor center. Two pathways are known for complex synthesis reaction with a generated transition-metal complex fragment and reaction with metal atoms by the metal-vapor synthesis method. [Pg.78]

The first authenticated borole (94) was made by the exchange reaction of phenylboron dichloride with l,l-dimethyl-2,3,4,5-tetraphenylstannole (93) (Eq. 29)w in toluene. [Pg.380]

However, the pseudo-borole 95 stemmed from another reaction of 96. Unknown to the earlier researchers who reported the synthesis of 95,94 their attempted preparation of 96 instead gave partly 98, a rearrangement observed previously,95 whereupon the reaction of 98 with PhBCl2 yielded phenyl(bis(2,3,4-triphenyl-l-naphthyl)borane, the actual identity of pseudo-borole 95 (Eq. 31). [Pg.381]

The first mixed metal borole cluster 22, which contains a planar Re2Pd2 array, was prepared via reaction of the [(r/s-H4C4B-Ph)Re(CO)3] anion with PdCl2(NCPh)2.25 In this electron-deficient system, the Pd atoms are formally 14e centers, stabilized by metal-metal binding with each other and with the Re atoms. [Pg.9]

Solid czs-1,2-diols and pyrocatechols react quantitatively with phenyl-boronic acid to form the phenylboronic esters upon stoichiometric milling. The water of reaction is taken up by the crystals and can be removed in a vacuum [90]. Thus, the aliphatic diols 186 and 189 give the borolic esters 188 and 190 with 100% yield (Scheme 25). Equally successful is the reaction of pyrocatechol (191) and 187. The reaction mixture is heated to 80 °C after milling at 0 °C. [Pg.130]

Dioxa-, oxathia-, and dithiaboroles undergo efficient transmetallation with alkynyl stannanes, furnishing the 5-alkynyl boroles. Thus the reaction of bis(trimethylstannyl) acetylene 273 with 2 equiv of bromoboranes 272 in toluene at room temperature furnishes air-sensitive boroles 274 as colorless solids in good yield (Equation 10) <2004EJI4223>. [Pg.639]

The typical preparation of the cyclic boroles from acyclic starting materials usually involves acid base chemistry or transacetalization protocols. 1,3,2-Diazaborolidines, such as 311 and 313, are readily available via the reaction of the corresponding amines 310 and 314 with boron tribromide (BBr3) and boron halide 312 (Scheme 51) <2006JCD3777>. [Pg.644]

The use of high-temperature (200 °C) thermal reactions for the synthesis of dibenzoboroles from 2-biphenyldialk-ylboranes was first realized by Kbster and Benedikt <1963AG419>. It was later shown that the pyridine adduct of 2-biphenylborane could also be converted by thermolysis to the corresponding pyridine adduct of dibenzoborole <1973JOM33>. In the recent literature, there have been no reports on the use of thermal and photochemical methods to prepare borole derivatives. [Pg.1230]

Boroles are readily reduced to the respective dianions owing in part to the empty p orbital on the boron atom. The reduction of 6-(4-/i< t/-butylphenyl)-3-/i t/-butyl-5-(bis-2,6-(4-/< /r-butylphenyl)phenyl)dibenzoborole 37 with excess lithium powder in diethyl ether suspension at — 10°C led to deep red crystalline dianionic bis(diethylether)dilithium salt 38. An attempt to obtain transition metal complexes by metathesis reactions of transition metal halides SnCU,... [Pg.1230]

The construction of a borole ring that is part of a metal complex from zirconium-coordinated 1,3-dienes and tris(pentafluorophenyl)borane has been recently introduced. Tris(pentafluoro-phenyl)borane is widely used as an activator of metallocene-based polymerization catalysts because of its resistance to aryl-transfer reactions, it acts as the boron source. The reaction utilizes the zwitterionic 14-electron bis(allyl)zirconium complexes 72 and 73 which are converted to the corresponding complexes 74 and 75 via activation of one of the C-H bonds of the B-CH2 moiety... [Pg.1235]

The reagent (1) is prepared in 80% yield by the reaction of catechol with borane in T11F. The borole reacts with olefins at 100° to give the corresponding 2-alkyl-... [Pg.25]


See other pages where 1//-Boroles, reactions is mentioned: [Pg.173]    [Pg.99]    [Pg.584]    [Pg.381]    [Pg.7]    [Pg.15]    [Pg.320]    [Pg.131]    [Pg.132]    [Pg.637]    [Pg.32]    [Pg.639]    [Pg.52]    [Pg.167]    [Pg.187]    [Pg.53]    [Pg.1229]    [Pg.1236]    [Pg.1236]    [Pg.499]    [Pg.499]   
See also in sourсe #XX -- [ Pg.79 , Pg.169 ]

See also in sourсe #XX -- [ Pg.79 , Pg.169 ]




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Borole

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