Borate dihydro

Primary aliphatic nitro compounds can be reduced to nitriles with sodium dihydro(trithio)borate " or with f-BuN=C/BuN=C=0. Secondary compounds give mostly ketones (e.g., nitrocyclohexane gave 45% cyclohexanone, 30% cyclohexanone oxime, and 19% A-cyclohexylhydroxylamine). Tertiary aliphatic nitro compounds do not react with this reagent. See also 19-41. 

SYNTHESIS OF (45, 55)-[(f -l,5-CYCLOOCTADIENE)- 2-(2-PHEN YL-5-METHYL, 5-DIHYDRO-OXAZOL-4-YL)-1,3-DIPHENYL-2-DIPHENYLPHOSPHINITE-PROPANE IRIDIUM(I)]-TETRAKIS[3,5-BIS(TRIFLUOROMETHYL)PHENYL]BORATE... 

Cyclooctadiene)- 2-(2-phenyl-5-methyl-4,5-dihydro-oxazol-4-yl)-l,3-diphenyl-2-diphenylphosphimte-propane mdium(l)]-tetrakis[3,5-bis(tri-fluoromethyl)phenyl]borate (1.72mg, l.Opmol). The catalyst is available from Strem Chemicals, Inc. (catalogue no. 77-5020). 

H2Bpz(Me2pz) = dihydro-(l-pyrazolyl)(3 -dimethyl-l-pyrazolyl)borate ... 

The outcome is more complex in the naphthalene series, where both the position of attack and the competition by rearomatization depend on the reagent chosen and conditions. Monocyanonaphthalenes are benzylated only by />-methoxytoluene, or by m- or />-methoxyphenylacetic acids, not by (poly)methylbenzenes [23,199]. 1,4-Dicyanonaphthalene reacts easily with toluene and a variety of precursors of the benzyl radical (alkylbenzenes [200-205], benzylsilanes, stannanes [206], and borates [56], as well as phenylacetic acids) [207] giving three types of products, viz. l-benzyl-4-cyanonaphthalenes, 1- or 2-benzyl-l,2-dihydro-l,4-dicyanonaphthalenes and dibenzobicyclo[3.3.1]nonanes resulting from the formation of a second carbon-carbon bond (Schs. 12 and 13). 

Borat (Bis-[ammoniak]-dime-thylboretio)-Dimethyl-dihydro-XIII/3b, 818... 

Di- and triorgano tin complexes of dihydro and diphenyl bis(pyrazolyl)borates are chelated through the two nitrogen donors to give five-coordinate complexes. Bis- and... 

BFaN, Borate(III), tetrafluoro-, tetrafluoro-ammonium (1 1), 24 42 BFi303Te3, Tellurate(VI), pentafluorooxo-, boron(3 + ) (3 1), 24 35 BKCsHie, Borate(l-), (cyclooctane-1,5-diyl)dihydio-, potassium, 22 BLiCaHu, Borate(l-), (cyclooctane-1,5-diyl)dihydro-, lithium, 22 199 BNCaHia, Borane, (dimethylamino)diethyl-, 22 209... 

Dihydropyridines generated from pyridinium salts carrying electron-withdrawing substituents at the 3 position by borohydride reduction are generally resistant to further reduction. The dihydro derivatives of 1-methyl-3-cyanopyridine, 68, 69, and 70, were recovered unchanged when treated with borohydride in water. Only 1,2-dihydro-l-methyl-3-cyano-pyridine (68) was converted to the tetrahydropyridine 71 when trimethyl borate was added to the reaction medium. Diborane/water achieved the same conversion, while added boric acid returned the starting materials. ... 

The enantioselective cyclopropanation of styrene with diazoacetic esters has been tested to evaluate a variety of other chiral copper catalysts, but the enantiomeric excesses were never as high as in the aforementioned cases. With a chiral 1,6-bis(4,5-dihydro-l, 3-oxazol-2-yl) ligand, the ee-values dropped to 28% trans) and 0% (c/s). Similar low values were observed when chiral derivatives of 2,2 -bipyridyl and related chelating compounds were used as ligands.Only moderate ee-values also resulted when copper(Il) tartrate, or the catalyst derived from copper(I) triflate and borate 3, was applied. 

Die Reduktion des 4,5-Dihydro-l,3-thiazolins mit Natrium-tetrahydroborat bzw. -cyano-trihydro-borat fiihrt iibenviegend zu offenkettigen Mercaptoaminen. 

A facile synthetic route to a-santalol (105) from the previously known aldehyde (106) has been reported by Corey et a/. in which a stereospecific modified Wittig reaction [(i) ethylidenetriphenylphosphorane, (ii) n-butyl-lithium, and (iii) paraformaldehyde] yielded the desired cis-isomer. Erman and co-workers, in a continuation of their synthetic work on the santalols, have reported the preparation of -santalol (107) from 3-methylnorcamphor. The route also provided a sample of the tmns-isomer which had previously been considered to be the natural isomer. The use of a borate ester as a protecting group for a hydroxy-function facilitated the synthesis of dihydro- -santalol (108) as outlined in Scheme 3. (These borate esters are stable to anhydrous acid or base but are readily hydrolysed in aqueous media.)... 

Light induced electron transfer from an amine to an excited arene leading to a contact radical ion pair is proposed to account for the products observed when 9,10-dicyanoanthracene is irradiated in wet benzene in the presence of an a-aminoketone. The non-polar solvent maintains the proximity of the radical ion pair which would normally then undergo non-productive back electron transfer however, in this case the ion pair reacts, ultimately to furnish 9,10-dihydro-9,10-dicyanoanthracene along with products of fragmentation of the a-aminoketone. Alkyl borate and borohydride salts can also serve as electron donors in the photoreduction of aryl cyanides and aryl halides and an abstract of a report on this topic has appeared. ... 

The dione (100) reacted exclusively at the exocyclic carbonyl in a synthesis of methyl 9-cis- (101) and 9-rra/i5 -trisporates B. Although ( )-dihydro-j8-santalol (103) was obtained from (102) in 90% yield if the hydroxy-group was protected as the borate ester, use of unprotected (102) gave predominantly the isomeric olefin (104). Similarly the hydroxy-ketone (105) gave the olefin (106), but similar rearrangements did not occur using the isopropylidene- or ethoxycarbonylmethylene-phosphoranes. 

LLactame liefem durch Alkylierung mit Dimethylsulfat Oder Triethyloxoniumtetrafluoro-borat und anschlieBende Deprotonierungmit Kaliumcarbonat 2-Ethoxy-3,4-dihydro-azete22 ... 

The preparations of lithium and sodium (cyclooctane-1,5-diyl)dihydro-borates(l-) in tetrahydrofuran proceed via isolable, stable etherates. These can be made solvent-free simply by heating under vacuum. 9-Borabicyclo[3.3.1 ]-nonane dimer (9-BBN) can easily be prepared from cycloocta-1,5-diene2 by reaction with tetraethyldiborane(6), tetrahydrofuran-borane8,9 or dimethyl sulfide-borane.10 The synthesis of alkali metal (cyclooctane-1,5-diyl)dihydroborates is achieved by addition of 9-BBN to a suspension of the alkali metal hydride in tetrahydrofuran. Lithium hydride reacts more slowly than sodium or potassium hydride. The reactions are brought to completion by heating under reflux. 

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