Boron trifluoride naming

Fig. 5) with olivetol (5.2) in the presence of boron trifluoride etherate, BF3 0C(C2H5)2 with CBD as a key intermediate. This one-step synthesis of A9-THC is also used for the production of synthetic dronabinol, which is used in the medicinal application named Marinol. The mechanism of this synthesis is particular described by Razdan et al. [71] and is shown in Fig. 5... 

The synthesis of the representative compound of this series, 1,4-dihydro-l-ethyl-6-fluoro (or 6-H)-4-oxo-7-(piperazin-l-yl)thieno[2/,3/ 4,5]thieno[3,2-b]pyridine-3-carboxylic acid (81), follows the same procedure as that utilized for compound 76. Namely, the 3-thienylacrylic acid (77) reacts with thionyl chloride to form the thieno Sjthiophene -carboxyl chloride (78). Reaction of this compound with monomethyl malonate and n-butyllithium gives rise to the acetoacetate derivative (79). Transformation of compound 79 to the thieno[2 3f 4,5]thieno[3,2-b]pyhdone-3-carboxy ic acid derivative (80) proceeds in three steps in the same manner as that shown for compound 75 in Scheme 15. Complexation of compound 75 with boron trifluoride etherate, followed by reaction with piperazine and decomplexation, results in the formation of the target compound (81), as shown in Scheme 16. The 6-desfluoro derivative of 81 does not show antibacterial activity in vitro. 

Boron trifluoride etherate is used as a catalyst in many organic reactions namely, alkylation, polymerization and condensation reactions. 

Unsaturated sugars, namely glycals, such as 3,4,6-tri-Oacetyl-l, 5-anhydro-2-dcoxy-D-r//v/-/w7o-hex-1-enetol and the d-/v.yo epimer react with xenon difluoride in the presence of a boron trifluoride-diethyl ether complex to give a mixture of C2 epimeric fluorides.45,46 Tri-O-acctyl-D-galactal treated with xenon difluoride in trichlorofluoromcthane below 5 C forms after hydrolysis (0.5 M HC1) 2-deoxy-2-fluoro-D-galactose in 63% overall yield.47... 

A new synthesis of the pyran (251), confusingly named linaloyl oxide, has been reported. 2,6-Dimethyl-l,2-epoxyhept-5-ene gave (252) with 2-lithio-l,3-dithian almost quantitatively, and boron trifluoride-catalysed cyclization to (253) readily led to (251).353... 

He and his students developed C-alkylation with quaternary ammonium salts and nucleophilic displacements on such salts, including the stereochemistry. His name is immediately associated with important innovations in the use of polyphosphoric acid for inter- and intramolecular condensations, cyclizations, and functional conversions in organic chemistry. He pioneered the use of boron trifluoride as an efficient catalyst in the Fischer indole synthesis and discovered new reactions of anils, including Diels-Alder reactions. He and his students delineated the requirements for disproportionation of tertiary amines. He developed the synthesis and chemistry of arylboranic acids. One of his fundamental ideas was for the incorporation of sufficient boron into organ-specific drugs that they could then be... 

Similar reform in the nomenclature of polyhalogen compounds may come some day, but for the present we consider it imprudent to do more than make a start. Thus the correct names for BF3 and for CICHjCHjCI surely are boron trifluoride and ethylene dichloride, and we feel no restraint from using them. However, although the names... 

Redactiaa of at-luMteUmes Treatment of x-bromoketones with lithium iodide and boron trifluoride in ether or THF at room temperature affords the parent ketone in high yield. The hydrogen was eventually found to originate, presumably as water, in the lithium iodide (Alfa Inorganics, anhydrous ). Only one exception to the reduction was observed, namely a-bromocamphor failed to react. The procedure is also effective for some x-chloroketones (phenacyl chloride, 2-chloropentanone), but fail.s for hindered chloroketones (oi-chloronorbomanone). 

Of the various types of higher order compounds which should be named as coordination compounds, only molecular addition compounds have not been considered. The rules for naming inorganic compounds indicate that (CHaJsN-BF would be called compound of boron trifluoride with trimethylamine., However, Davidson and Brown (4) suggest that this substance be called trimethylamine-boron trifluoride. In general, that molecule which donates a pair of electrons (base) is given first followed by the acceptor molecule (acid). Similarly, (CH3)2S-A1(CH3)3 would be known as dimethyl sulfide-trimethylaluminum. If these were named as coordination compounds, the names would be (trimethylamine)trifluoroboron and (dimethylsulfide)trimethylalu-minum. 

As a catalyst for the ring condensation Lewis acids such as for instance zinc chloride, zinc bromide, boron trifluoride, ferric chloride, stannic chloride, titanium chloride or iodine are used, zinc chloride and zinc bromide having proved to be more particularly suitable. Water binding substances such as neutral substances as for instance magnesium sulfate, sodium sulfate, calcium sulfate or molecular sieves may be used, the last-named having proved more particularly suitable. 

Whereas these and other reports did not indicate the possibility of 1,4-cuprate additions to activated dienes, Yamamoto and co workers" showed in their seminal contributions that this is indeed feasible while the reaction of methyl sorbate with the Gilman cuprate M-Bu2CuLi provided exclusively the 1,6-addition product, the reagent formed from butylcopper and the Lewis acid boron trifluoride led to the 1.4-adduct as the major product (equation 15). The synthetically veiy useful organocopper compounds RCu have been named Yamamoto reagents. In certain cases, the regioselectiv-... 

Various substituted benzimidazoles have been synthesized in very good yields in solvent-free conditions from 1,2-diaminobenzene and aldehydes in the presence of titanium(IV) chloride as a catalyst. The method is applicable to most aromatic, unsaturated and aliphatic aldehydes and to substituted 1,2-diaminobenzenes without significant differences [14]. Several other catalysts, namely iodine [15], hydrogen peroxide [16], zirconyl(IV) chloride [17], boron trifluoride diethyl etherate [18], ytterbium perfluorooctane sulfonates [19,20], zeolite [11,21], and L-proline [22], have been effectively used for the synthesis of benzimidazole derivatives. 

Acylation of 3-substituted indoles is more difficult, however 2-acetylation can be effected with the aid of boron trifluoride catalysis." " Indoles, with a carboxyl-containing side-chain acid at C-3, undergo intramolecular acylation forming cyclic 2-acylindoles." Intramolecular Vilsmeier processes, using tryptamine amides, have been used extensively for the synthesis of 3,4-dihydro-p-carbolines, a sub-structure found in many indole alkaloids (P-carboline is the widely used, trivial name for pyrido[3,4-fc]indole). Note that it is the imine, rather than a ketone, that is the final product the cyclic nature of the imine favours its retention rather than hydrolysis to amine plus ketone as in the standard Vilsmeier sequence " this ring closure is analogous to the Bischler-Napieralski synthesis of 3,4-dihydro-isoquinolines (9.15.1.7). 

The complexes of urea and thiourea with boron trifluoride have been studied and, as with other boron trifluoride complexes, the shifts are very similar namely 19 2+0-3 p.p.m. [with respect to (MeO)aB]. A similar shift was observed for the more complex adducts with cadmium chloride or nickel bromide. It was found that dimethyl ether-boron trifluoride (shift of 17-6) and di-t-butylthiourea-boron... 

Oxidative dimerisation of a guaiacyl system, namely prestegane B, in dichloromethane containing boron trifluoride etherate was achieved in 80% yield by addition to a stirred suspension of ruthenium dioxide dihydrate in dichloromethane containing triflic acid/triflic anhydride (in the proportions 8 2 1) at 0°C followed by reaction for 3 hours (ref.73). 

Open-chain diazo-a,a -dicarbonyl compounds form complexes with boron trifluoride. There are two types of such complexes, as shown by Fahr and Hormann (1965) by means of IR spectra. In the solid state, the complexes show similarities to aromatic diazonium compounds, they have a quasi-aromatic six-membered chelate ring (2.35). They also undergo a reaction typical of solid aromatic diazonium salts, namely the Balz-Schiemann reaction (see Zollinger, 1994, Sect. 10.4), in which the corresponding fluoro-a,ct -dicarbonyl compound 2.36 is formed (2-12) (Prim and Schank, 1978). In benzene solution, however, the 1 2 complex is not chelated, rather Fahr and Hermann s IR data indicate structure 2.37. 

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