Acetonaphthones

Figure 6.10. Rate constants for quenching of sensitizers by cis- and trans-stilbenes (open and filled circles, respectively). Sensitizers are as follows (1) tri-phenylene, (2) thioxanthone, (3) phenanthrene, (4) 2-acetonaphthone, (3) 1-naphthyl phenyl ketone, (6) crysene, (7) fluorenone, (8) 1,2,5,6-dibenzanthracene, (9) benzil, (10) 1,2,3,4-dibenzanthracene, (11) pyrene, (12) 1,2-benzanthracene, (13) benzanthrone, (14) 3-acetyl pyrene, (15) acridine, (16) 9,10-dimethyl-l,2-benzanthracene, (17) anthracene, (18) 3,4-benzpyrene.<57> Reprinted by permission of the American Chemical Society.

Irradiation of a mixture of hexadiene isomers in 1,1-dichloroethylene with /J-acetonaphthone gave four cyclobutane derivatives<54) ... 

Table 10.8. Effect of Temperature on the Product Distribution from the a-Acetonaphthone-Sensitized Photoaddition of Cyclopentadiene to cis- and trans-Dichloroethylene<60>...

The decomposition of methanesulphonyl azide in isopropyl alcohol could be effected by selective irradiation of 2-acetonaphthone instead of benzophenone 21>. Since 2-acetonaphthone triplets are incapable of hydrogen abstraction from isopropyl alcohol 22>, initiation must occur via transfer of excitation energy to the azide. A marked difference was observed from benzophenone sensitization in that the reaction was extremely slow, gave a nitrogen yield of only 68%, and produced a yellow solution 21>. 

The photoreductions of a number of carbonyl compounds with either lowest mr or jiji triplet states in the presence of tributyltinhydride are reported24. The carbonyl compounds include cyclohexanone and acetone which possess nrr lowest-energy triplets, and 2-acetonaphthone, 1-naphthaldehyde and 2-naphthaldehyde which possess lowest-energy mr triplets. In the case of the two njr triplets, a simple mechanism is proposed which involves the abstraction of a hydrogen atom from the tributyltinhydride by the triplet state... 

Immobilized catalysts on solid supports inherently have benefits because of their easy separation from the products and the possibility of recycling. They are also expected to be useful for combinatorial chemistry and high-throughput experimentation. The polystyrene-bound BINAP/DPEN-Ru complex (beads) in the presence of (CH3)3COK catalyzes the hydrogenation of l -acetonaphthone with an SCR of 12 300 in a 2-propanol-DMF mixture (1 1, v/v) to afford the chiral alcohol in 97% ee (Fig. 32.35) [113]. This supported complex is separable... 

Fig. 32.35 Hydrogenation of I -acetonaphthone with the polymer-bound BINAP/DPEN-Ru catalyst.

Fig. 32.50 Hydrogenation of 1-acetonaphthone with a DM-BI-PHEP/(S,S)-DPEN-Ru catalyst.

For example, the hydrogenation of 1-acetonaphthone with a catalyst system consisting of RuCl2[(X)-BINAP](DMF)n, (S.S)-1.2-diphenylethylenediamine... 

Electrochemistry offers new routes to the production of several commercially relevant a-arylpropionic acids, used as non-steroidal anti-inflammatory agents (NSAI) [178,182]. A preparative method based on sacrificial Al-electrodes has been set up for the electrocarboxylation of ketones [117,183-187] and successfully applied to the electrocarboxylation of aldehydes, which failed with conventional systems. The electrocarboxylation of 6-methoxy-acetonaphthone to 2-hydroxy-2-(6-methoxynaphthyl)propionic acid, followed by chemical hydrogenation to 2-(6-methoxynaphthyl)-2-propionic acid - one of the most active NSAI acids - has been developed up to the pilot stage [184,186],... 

Fig. 23. (—) spectrum at atmospheric pressure (—) spectrum under 100 atm of oxygen. 1-naphthaldehyde, 0.20 M in n-hexane 2-acetonaphthone, 2.00 M in chloroform 1-acetonaph-thone, 1.00 M in chloroform. Path length 8.5 cm. (From Warwick and Wells, Ref. >)... 

The photocyanation of 1-nitroazulene was accompanied by a dark reaction and was thus less suitable for mechanistic studies than the methoxylation. 2-Acetonaphthone (Et=59 kcal mole i) and 2-naphthophenone ( t=60 kcal mole i) were found to be efficient sensitizers for the disappearance of 1-nitro azrdene in the methoxylation reaction. The measured rate of product formation, however, seemed to be much lower than the rate of starting material disappearance. This effect has been attributed to sensitized decomposition of the product 104)... 

In contrast to the case of naphthaldehydes and acetonaphthones, irradiation of the absorption band of 10-methylacridone (AcrCO) results in fluorescence at 413 nm in MeCN [113]. When Sc(OTf)3 is added to an MeCN solution of AcrCO, the absorption bands of 10-methylacridone is red-shifted due to the 1 1 complex... 

Remarkable positive shifts of the °red values of the singlet excited states of the metal ion-carbonyl complexes as compared to those of the triplet excited states of uncomplexed carbonyl compounds (Table 2) result in a significant increase in the redox reactivity of the Lewis acid complexes versus uncomplexed carbonyl compounds in the photoinduced electron-transfer reactions. For example, photoaddition of benzyltrimethylsilane with naphthaldehydes and acetonaphthones proceeds efficiently in the presence of Mg(C104)2 in MeCN, although... 

The effect of the tropos complex 31b with (S,.S)-DPEN can be observed in the hydrogenation of I -acetonaphthone 16 as compared with the results using ( )-10b/(S,S)-DPEN bearing racemic and atropos XylBlNAP (Table 8.10). ... 

Other hydrogenation methods are less chemoselective. Use of Raney nickel provides hydroxylamines in low yield °. Hydrogenation of 1-acetonaphthone oxime over rhodium-chiral phosphine catalysts was found to proceed under harsh conditions and provided low... 

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