Substituents naphthyl

Rotation about the 1,1 -bond is resisted by van der Waals interactions between the hydrogens shown in the structures. These hydrogens crowd each other when the two naphthyl groups are coplanar, and the racemization process requires tjie hydrogens to move past each other. The existence of enantiomeric substituted biphenyls also depends on steric interactions between substituents. The relationship between the rate of racemization and... 

The halide groups can be replaced by other substituents like hydride or alkyl [86]. When the naphthyl (np) RuHnp(dmpe)2 is heated, the ligand undergoes an internal metallation to afford a dimer [87] (it was originally believed to be a monomer), though Ru(dmpe)2 has been isolated by photolysis of its dihydride, in matrixes at 12K (Figure 1.29) [88],... 

Gore et al.426 have used chloroform as a solvent for acetylation catalysed by aluminium chloride and at 45-55 °C find that a 2-methoxy substituent in naphthalene increases the reactivity of the 1 position 1.72 times, of the 6 position 3.8 times, and of the 8 position, 0.9 times the former and latter of these results indicate a considerable steric effect. Likewise, a 2-bromo substituent caused the reactivity of the 6 and 8 positions to be 0.63 and 0.58 times that of the corresponding positions in the unsubstituted compound. At 20-25 °C the relative reactivities of some polycyclics were as follows427 1-naphthyl, 1.0 3-phenanthryl 0.64 9-phenanthryl, 0.02 1-phenanthryl, 0.29 2-naphthyl, 0.28 2-phenanthryl, 0.12 4-phenanthryl, 0.0085. Some of these results seem to be due to steric hindrance, and the large difference in reactivity of naphthalene and biphenyl seems erroneous. 

The log krcl values for the coefficients obtained at ionic strength 0.1 plotted satisfactorily using the Yukaw-Tsuno equation612 withp = —2.96 and r = 0.65, and this demonstrates the difference between this reaction and that carried out in carbon tetrachloride the point for the 2-naphthyl substituent also plots quite... 

The spiro compound 206 was prepared in five steps from (S)-l-naphthyl-ethylamine and was composed of a mixture of imine and enamine tautomers. Reduction of the imine function by sodium borohydride occurred on the less hindered si face, leading to the diamine with the R configuration of the newly formed stereo center, then the N-benzyl substituent was removed by hydrogenolysis to give 207 with good overall yield [98] (Scheme 30). 

In 1982, the Schaap group demonstrated that chemiluminescence can be induced by the addition of a base to dioxetanes bearing a phenolic substituent [11]. Herein, the same group presents a method utilizing aryl esterase to catalyze the cleavage of a naphthyl acetate-substituted dioxetane in aqueous buffer at ambient... 

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