2-naphthylmethyl group

Deprotection. Removal of the 2-naphthylmethyl group from 2-NpCH20R and oxidative cleavage of oximes and tosylhydrazones with DDQ proceed under mild conditions. Smooth and selective transformation of RNBn2 to RNHBn at room temperature by DDQ in dichloromethane containing some water is observed. ... 

Heptakis 6-0-t-butyldimethylsilyl-P-cyclodextrin, on reaction with 4-chloro-methyl-A -methyl-2-nitroaniline, affords the mono-3-substituted benzyl ether. P-Cyclodextrin carrying a 2-(naphthylmethyl) group at 0-6 exists with the aromatic rings within the cavity to an extent which is very temperature dependent. Temperature can therefore be used to control the degree of complexing of the aromatic system with a fluorescent naphthalene compound. Heptakis-[2,3-di-0-acetyl-6-deoxy-6-iodo]-P-cyclodextrin treated with 6-methoxycarbonyl-2-naphthol allowed access to the compound having naphthoic acid substituents at all of the primary positions, and this forms a very stable 1 1 complex with a merocyanine laser dye which is a mimic of the antenna function in photosynthesis and shows promise as a photochemical microreactor. Mono-[6-0-(8-qui-nolyl)]-P-cyclodextrin has been reported, and the stabilities of inclusion complexes with amino acid guests have been described. ... 

Not only the copolymers of AMPS and DodMAm but also the copolymers of AMPS and a methactylamide A -substituted with cyclododecyl, adamantyl, or naphthylmethyl groups (Chart 3) form either a unimolecular flower-like or higher-order micelle (i.e., tertiary structure) depending on the hydrophobe content in die copolymer. An important feature for these copolymers is that such unimer micelles are formed even at hi polymer concentrations in water. Some of the requiate structures for polymers to form unimer micelles are (i) the hydrophobes should be sufficiently bulky, (ii) the sequence distribution of hydrophobic and electrolyte monomer units should be random, and (iii) the hydrophobes should be linked to the polymer main chain via amide spacer Ending (22). 

The first case was discovered by Hans Dahn and U. Solms. " These authors had prepared A -9-fluorenyl-A -methyl-A -(l-naphthylmethyl)amine (343) by reduction of the naphthoyl precursor with lithium aluminum hydride in refluxing DEE. When the reaction was repeated in refluxing THF, W-methyl-A -9-[9-(l-napthylmethyl)fluorenyl]amine (344) was isolated after 16 h in 56% yield. This time the hy de had acted as a reducing agent and as a base at the same time, triggering a Stevens-like [l,2]-migration of the naphthylmethyl group to the unionized 9-fluorenyl position. The tertiary amine 343, the... 

Scheme 1-269. Conversion of the tertiary amine 343 into the secondary amine 344 by [l,2]-migration of the 1-naphthylmethyl group.

The two high-affinity compounds, the 2-naphthylmethyl and the 3,3-diphenylpropyl analog, 13 and 11, respectively, constitute the third group in the analysis of the correlation of lipophilicity with affinity, both compounds showing higher affinity for the... 

The fact that the naphthyl carbonyl compounds attain a ir,ir triplet is somewhat analogous to the quenching of the benzophenone n,n triplet by added naphthalene (Table II), and is consistent with the triplet energy levels (benzophenone 69 kcal mole-1 naphthalene 60 kcal mole-1). This intramolecular energy transfer takes place even if the naphthalene is insulated from the benzophenone by a methylene group, since 4-(l -naphthylmethyl) benzophenone 24 emits from the naphthalene moiety when irradiated in the carbonyl n-> tt region.82 The photochemical reactivity of this ketone has not been reported. 

In 1992, Legros and Fiaud found palladium-catalyzed benzyiic alkylation of naphthylmethyl and 1-naphthylethyl esters 103 with sodium dimethyl malonate 104 in dimethylformamide (DMF) to give the corresponding benzyiic alkylated products 105 in high yields (Equation (41)). " When trifluoroacetyl group is used as a leaving group of the ester partner, catalytic alkylation proceeds quite smoothly even at room temperature. In this reaction system, no reaction occurs with benzyiic acetates. 

All the above compounds yield excimer fluorescence when excited in room-temperature solution. However, because the rotational potential of the C—X bond and the nonbonded interactions of the substituents of the X atom differ from those of the C—C bond 126), the amount of excimer fluorescence from R(C—X—C)R differs from that of R(C—C—C)R. The heteroatom X can also influence the rotational state of the side groups R, as illustrated by the formation of the anti-photodimer in bis(l-naphthylmethyl)ether u2), but not in l,3-bis(l-naphthyl)propane 10). Finally, compounds having n 3 may exhibit excimer fluorescence, if the linkage contains one or more heteroatoms. For example, the—C—O—C—C— linkage in a,to-bis(2-naphthyl) compound allows excimer fluorescence to be observed in room-temperature solution39). 

Apart from lengthening the chain by one carbon atom, this reaction provides a compound with two readily modified functional groups. Many other halogen compounds offer a more complex picture. Radical-derived products are sometimes obtained, but in other cases a heterolytic mechanism must operate, for example to give a methyl ether when naphthylmethyl iodides are irradiated in methanol (5.651. 

Pyran decomposes in contact with moist air or adds but its tetrasubstituted derivatives, e.g. (155), are stable and are usefully converted into naphthalenes (156) by treatment with perchloric acid. A 4-benzyl or 4-naphthylmethyl substituent is essential. Pyran ring opening occurs and is followed by cyclization and elimination of a simple ketone which is formed from the 2- or 6-substituent. Alkyl groups at C-2 or C-6 are converted into the ketone more easily than a phenyl group (64LA(678)202). 

FIGURE 10.1 Some monosaccharide building blocks used in the assembly of (a) HA, (b) CS, and (c) heparin/HS showing the array of protecting groups. All, allyl Bn, benzyl Bz, benzoyl Fmoc, 9-fluorenylmethoxycarbonyl Lev, levulinyl NAP, 2-naphthylmethyl PBB, p-bromobenzyl Phth, phthaloyl PMB, / -methoxybenzyl PMP, p-methoxyphenyl TBDPS, ferf-butyldiphenylsilyl TBS, ferf-butyldimethylsilyl TCA, trichloroacetyl TDS, dimethylthexylsilyl Tol, 4-tolyl. 

The 2-naphthylmethyl ether group250 288 was used to protect a single primary hydroxy group in syntheses of tetra-. penta- and hexa-saccharide chains from respiratory mucins.289 The requisite building block 155.2 [Scheme 4.155] was prepared by O-alkylation of the cyclic stannoxane prepared from triol 155.1 using 2-naphthylmethyl bromide Deprotection was efficiently achieved under mild conditions using DDQ as exemplified by the conversion of 1553 to 155A. 

The results already described for [36] are similar to those obtained for N-methyl-N -(l-naphthylmethyl)aniline in that exciplex can be observed in relatively nonpolar solvents. This is not the case for [34 n = 1] and for [39 n = 1]. In these systems the amino group cannot directly interact with the 7t system of the anthracenyl and pyrenyl ring systems, but some interaction... 

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