Indoline moiety

The absorption bands for both quinoid and dipolar structures have been calculated by the PPP method.2,12 The calculations for a more simplified model of the colored form of some spirobenzopyrans using the normal parameters are shown in Table 2.12 In this case, the spiro carbon in the indoline moiety is ignored in the 7i-electron system, and the quinoid structure is assumed. 

In Grigg s approach to hippadine (37), he established the connection between the two phenyl rings via the Stille-Kelly reaction [45]. When diiodide 35 was submitted to the Pd(0)/ditin catalyst system, the intramolecular cyclization was realized to establish the C—C bond in lactam 36. Oxidation of the indoline moiety in 36 using 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) then delivered hippadine (37). Analogously, the intramolecular Stille coupling of dibromide 38 led directly to hippadine (37) [46]. 

Schneider et al. [63] investigated the photochemistry of the spiro-oxazine merocyanines pumping and probing at 570 nm in acetonitrile. The found that the solution bleached within the <5-psec pulse duration. The bleached state recovered with at least a biexponential behavior, and from their fluorescence decay measurements, three exponentials were required to fit the decay. They attribute these findings to the possibility of three merocyanine isomers that are in equilibrium. Their compounds feature geminal ethyl groups on the indoline moieties and this may influence the system as compared to NOSIl. 

In a model of gardmultine [544] the 18 -methyl is seen to lie over the indoline moiety thus providing an explanation of its low frequency absorption (<5 0-88). Treatment of [544] with hydrochloric acid gives the conformationally more mobile oxindole [545] which now shows absorption for the 18 -methyl protons at d 1-43. (324)... 

The treatment of 4,6-dichloro-5-aminopyrimidine 1198 with indoline 1197 gave 4-chloro-6-(2,3-dihydro-l//-indol-l-yl)-5-pyrimidinamine 1199 in 79% yield (Scheme 230) <2005JC0813>. Subsequent oxidation of the indoline moiety to the corresponding indole was achieved with DDQ in refluxing benzene to yield the indole-substituted pyrimidine 1200, the key compound in the cyclization reactions with various aldehydes and ketones leading to a novel heterocyclic scaffold consisting of indole-fused pteridines. 

Ct break point at 54°C. This temperature may correspond to the transition temperature (Tg) attributable to the local mode relaxation of polymer main chains. A long alkyl substituent at the nitrogen atom of the indoline moiety enhances the effect of local mobility of polymer chains on the thermal reversion. 

Substituents on the Indoline Moiety of Spiropyrans Inductive and Mesomeric Effects... 

The reactivity (photodegradation) of spiropyrans substituted on the aromatic ring of the indoline moiety has been rationalized in terms of inductive and mesomeric effects and quantified on the basis of the Hammett equation ... 

Vl/2 values. For substituents on the benzopyran ring, the o values were those used by the National Cash Register Company (NCR). Taft or McDaniel and Brown values28 were used for substituents on the indoline moiety for 5-substituted pyrans, CTpara values were found to be adequate. 

A CH3 group on C3 greatly decreases stability whereas QH5 substitution yields stabilization (Table 5, 47 vs. 48). It was noted that, in general, the rate constant k of the thermal bleaching reaction was not affected by the ct Hammett constants of substituents on the indoline moiety whereas for substituents on the chromene moiety EDGs produced an increase of k. 

From the results reported in the preceding tables, one can state that photochromes having the heterocyclic indoline moiety perform better in terms of both color-ability and fatigue resistance. It is interesting to compare the behavior of... 

As in InFl, the indoline moiety is in a trans position with respect to the carbonyl C(13)-0(3) group. Because of steric interactions between the syn-arranged bulky adamantylidene and indoline substituents, the latter is twisted... 

SERS) recorded. From the comparison of the SERS spectra of the photochromes with those of the indoline and chromene model molecules (Figure 9), it was established that the SERS spectra of SPP (4) and SPOX (3) are mainly dominated by the vibrational characteristics of the indolinic moiety. Moreover, the detailed assignment of the SERS data, performed on the basis of the vibrational analysis of the NIR-FT Raman spectra of the pure substances, has enabled deduction of the geometry of the adsorbed species,48 shown in Figure 10. 

Vinblastine (169) and Vincristine (170).— The alkaloids each possess two individual chromophores, an indole and a 6-methoxyindoline in vinblastine, an indole and an iV-formyl-6-methoxyindoline in vincristine. The indoline moiety is part of an aspidospermine-type skeleton and the indole part of a 5,18-chano-ibogamine skeleton. The mode of linkage of the two units (aromatic position of the indoline to the a-indolylic position of the indole) corresponds to that present in the voacamine group (see Section 9). 

The intermolecular variant of the above reaction between W-methylphthalimide (74) and a series of W-acylindole derivatives 75a-f was next examined [37, 38]. Compounds 75a and 75d-f produced the corresponding more sterically hindered oxetanes 76a and 76d-f in which the aromatic rings of the isoindolone and indoline moieties overlap (Scheme 19). Interestingly, in the cases of 75b, c, the initially formed oxetanes 76b-d were converted to a variety of products, presumably via the hydrolysis of the oxetanes, followed by ring opening of the indoline ring and subsequent reactions to produce 78-81. 

The clinically important anticancer drug vinblastine also incorporates two chromophores, the indole and indoline moieties, which are coupled through space. The biologically active molecule is... 

A photolabile precursor (170) of the amino acid, glycine (172) containing two phosphate groups attaehed to the indoline moiety at the 4-alkoxy position, has been synthethised by Ogden et al. This precursor released glycine (172) and the nitrosoindole by-product (171) on a sub-ms time scale upon irradiation with near-UV light (Scheme 47)7 ... 

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