Substituted alkanes, optical

The compound has four degrees of unsaturation (if it were a substituted alkane, its formula would be C,Hn,N), which indicates the presence of a phenyl ring, (A) dissolves in HCI and therefore is an amine. Since (A) releases with HONO, it is a 1° amine. Since (A) is optically active, it has a chiral C. The —NH cannot be on the ring since the two remaining C s cannot be positioned to give a chiral C. The —NH must be on the side chain. The compound is C H5CH(NH2)CH,. 

Next, we examine aliphatic hydrocarbons. First we study the nomenclature and reactions of alkanes. We examine the optical isomerism of substituted alkanes and also the properties of cycloalkanes. We then study unsaturated hydrocarbons, molecules that contain carbon-to-carbon double bonds and triple bonds. We focus on their nomenclature, properties, and geometric isomers. (24.2)... 

In regard to the stereoselectivity of the insertion process, Murray and coworkers have shown that the CH oxidation of substituted cyclohexanes by dioxiranes is, like the already discussed epoxidation, highly stereo-controUed . A specific case is c -decalin, which gives only the cis alcohol, as exemplarily displayed in equation 27. A similar stereoselective retention of configuration was also obtained for frawi-decalin and cis- and frawi-dimethylcyclohexanes"°. In fact, complete retention of configuration was demonstrated in the CH oxidation of chiral alkanes ". For example, the optically active (f )-2-phenylbutane was converted by either DMD or TFD" to (5 )-2-phenylbutan-2-ol (equation 28) without any loss of the enantiomeric purity (ep) in the product. 

Nucleophilic addition of sulfur ylides to C=0 double bonds is an important means of synthesis of epoxides [198], Because optically active epoxides are widely applied as versatile intermediates in the preparation of, e.g., pharmaceuticals, the asymmetric design of this sulfur ylide-based reaction has attracted much interest [199, 200, 212, 213], One aspect of this asymmetric organocatalytic process which has been realized by several groups is shown in Scheme 6.87A. In the first step a chiral sulfur ylide of type 204 is formed in a nucleophilic substitution reaction starting from a halogenated alkane, a base, and a chiral sulfide of type 203 as organocata-... 

Ono and Ware"" have measured the absorption, emission, and excitation spectra, the fluorescence decay times, and the quantum yields of a series of substituted diphenylmethylenes in rigid matrices at low temperatures. Acean-thrylene shows S2- So emission in hexane with a yield of 0.017 and lifetime of 4.3 ns. The low-temperature fluorescence spectra of bis-2-naphthyl-alkanes and their derivatives have been studied. Excimer formation is an activated process. The fluorescence and absorption spectra of 1,1-diphenyl-ethylenes have been analysed in some detail by Gustav and Bolke. " The S — Si transitions in trans isomers of phenylnaphthylethylenes have been assigned by picosecond absorption spectroscopy. Effects of solvent viscosity and the role of conformers in the mechanism of isomerization are elucidated. The production of non-equilibrium conformer concentrations in glassy solutions of diarylethylenes at 77 K due to restrictions imposed by the solid matrix has also been reported. Free jet excitation and emission spectra of diphenyl-butadiene show clearly the lowest excited Ag state and give a lifetime of 52.8 ns for 0-0 excitation.Electric field-induced charges in the optical... 

The property of chirality is determined by molecular topology, and there are many molecules that are chiral even though they do not possess an asymmetrically substituted atom. Examples include certain allenes, spiranes, alkylidenecyclo-alkanes, and biaryls as well as other specific examples. Some specific molecules that have been isolated in optically active form are given in Scheme 2.2. The configuration of these molecules is established by subrules in the Cahn-Ingold-Prelog convention. We will not describe these here. Discussion of these rules can be found in Ref. 1. 

The Co" complex [CoPcFig] have advantageous properties as electrocatalyst for the reduction of oxygen as compared to [CoPc] [39]. The Ru" complex [RuPcF, ] appeared to be an effective catalyst for the room tanperature oxidation of cycloalkanes [9]. Encapsulated in zeolite these species were used for catalytic oxidation of alkanes and alcohols [46]. In photoelectrochemical and (photo)conductivity studies it was shown that [ZnPcFig] behaves as n-type semiconductor in vacuo and photoconductor in the presence of oxygen [37, 47]. Due to its enhanced solubility in different solvents as compared to non-substituted [ZnPc] it has advantages for clinical application in photodynamic tumor therapy [11]. Perfluorinated In ", Ti and Zd phthalocyanines exhibit higher performance as optical limiters than non-fluorinated species [42]. 

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