Tolyl groups

Toliiic anilide, on hydrolysis, forms toluic acid and aniline, whereas beii2oic toluide yields benzoic acid and toluidine. It follows therefoie that, in the original compound, the first contains the hydroxyl neaier the phenyl group and the second nearer the tolyl group. 

All values in benzene. Ojl a t 30°, all other values at 20°. The numbers in parenthesis indicate the percentage of o-tolyl groups. 

Figure 61 The structure of the trialkyl calcate [Na(OEt2)][Ca(MeOC6H4CH(P(tolyl-p)2)3] 120, with only C, atoms of the p-tolyl groups displayed.

We referred earlier to the significance of reactions at the alkylidyne carbon atoms of the dimetal species. Our studies in this area are in a preliminary stage, but Schemes 1 and 2 summarise some chemistry at the bridged carbon centres for the compounds (1 ) and (3,)(12). It will be noted that protonation of the neutral bridged al ylidyne compounds yields cationic alkylidene species in which one C—C bond of the tolyl group is n2 co-ordinated to tungsten, a feature revealed by both n.m.r. and X-ray diffraction studies. 

In similar experiments in which an ethyl group was used in place of the para-tolyl group of compound V there was no rearrangement. Apparently aromatic but not aliphatic groups will migrate under these mild conditions. The same results have been obtained in experiments in which the radical is formed by a different method ... 

In this reaction para-xenyl and a-naphthyl groups migrate six times as readily as competing phenyl or para-tolyl groups.111... 

Fig-1 View of the pentanuclear assembly of [Fe2(totrz)5(NCS)4]2[Fe(totrz)2(NCS)2(H20)2] (p-tolyl groups and hydrogen atoms of the triazole have been omitted for clarity). Shining black, white, and black and white small spheres correspond to nitrogen, carbon and sulfur atoms, respectively. The larger black spheres correspond to iron(II) ions... 

A, and fl = 90.48°. The 2-pyridyl ring and p-tolyl group make dihedral angles of 29.7° and 55.3° respectively with the double bond plane. The inter-aryl dihedral angle is 106.5°. The data was obtained on crystals grown from a solution of the compound in anisole. A Picker FACS-1 diffractometer with CuK radiation was used for the measurements, or... 

Kinetic and mechanistic studies by Casey et al. provided further insight into the mechanistic details of the hydrogenation of ketones and aldehydes, using a more soluble analogue of Shvd s catalyst (with p-tolyl groups instead of two of the Ph groups) [72]. The kinetics of hydrogenation of benzaldehyde by the Ru complex shown in Eq. (43) were first order in aldehyde and first order in the Ru complex the... 

Reaction with solvent - The solvent influences the course of cationic reactions not only through its dielectric constant, but also because many substances used as solvents are far from inert in these reactions [22, 23]. Although much more experimental material is required before a full treatment of the subject becomes possible, at least one example, the cationic polymerisation of styrene in toluene, is amenable to quantitative discussion. Experiment shows that polymerisation is rapid and complete, the molecular weight is low and the polymer contains para-substituted rings which are almost certainly tolyl endgroups [22]. Theoretically, a polystyryl carbonium ion can react with toluene in six different ways, only two of which (a.l and b. 1 below) can lead to tolyl endgroups in the first case the tolyl group is at the end of the terminated chain, in the second it is the start of a new chain. The alternative reactions can be represented as follows... 

Furukawa and co-workers (368,369) succeeded in applying the softer dicationic Pd-BINAP 260 as a catalyst for the 1,3-dipolar cycloaddition between 225 and 241a (Scheme 12.82). In most cases, mixtures of endo-243 and exo-243 were obtained, however, enantioselectives of up to 93% ee were observed for reactions of some derivatives of 225. A transition state structure has been proposed to account for the high selectivities obtained for some of the substrates (368). In the structure shown in Scheme 12.82, the two phosphorous atoms of the Tol-BINAP ligand and the two carbonyl oxygens of the crotonoyl oxazolidinone are arranged in a square-planar fashion around the palladium center. This leaves the ii-face of the alkene available for the cycloaddition reaction, while the re-face is shielded by one of the Tol-BINAP tolyl groups. 

Methyl groups in position 7 of triazolopyridines of type 2 are sufficiently reactive to condense with anils, giving diarylakenes such as compound 299 27o,27i Methyi groups in positions 6 and 8 are not reactive in condensation, but a bis adduct (300) has been obtained by using a reactive 2-tolyl group. A methyl group in position 3 of system 3 is also sufficiently active to condense... 

An unusual oxidative breakdown of a p-tolyl group to a carboxylic acid (688) is accomplished in moderate yield without degrading the chroman system (51JCS76) and the stability of this system to oxidation (cf. chromone, Section 2.23.9.3) is further illustrated by the conversion of an ethyl to a carboxyl group in the formation of 2,4,4-trimethylchroman-2,7-dicarboxylic acid (689) (57JCS3060). 

Pyrazoles substituted in the 1-, 3-, or 5-position with a p-tolyl group are converted to the corresponding stilbenyl derivatives, with benzalan-ilines in the presence of potassium hydroxide, only in very low yield (Table X). Thus, 1,3-di-(p-tolyI)-5-phenylpyrazole (128) reacts with benzalaniline to give only a 2% yield of the l,3-di(stilben-4-yl)-5-phenylpyrazole (129).11... 

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