Optically active amines. 34. Application of the benzene chirality rule to ring-substituted phenylcarbinamines and carbinols

Multiphoton Ionization and Circular Dichroism: New Experimental Approach and Application to Natural Products

“…www.chemphyschem.org in the solution. [17][18][19] This can be taken as a verification of our values although the size of g is, by a factor of three, smaller than in the gas phase. These numbers are listed in Table 2, together with the results for nine further molecules, most of which are natural products.…”

“…water [17,18] , ethanol [19] (7) S-(À)phenylethylamine 266/-+ 0.65 AE 0.05 phenol + 0.1 water [19] (8) R(À)a-phellandrene 266/-À0.16 AE 0.03 xylene À0.17 gas phase [26] (9) 1(S)5(S)(À)a-pinene 222/-+ 0.38 AE 0.08 xylene + 0.38 gas phase [27] (10) S(À)limonene 213/-À0.16 AE 0.06 xylene À0.13 gas phase [28] [a] Wavelengths of the used one-or two-color REMPI. Table 2.…”

“…Reference [b] Literature g [%] [c] Literature solvent [c] (1) 1(R)(+)camphor 295/213 + 8.0 AE 0,3 -+ 8 gas phase [20] (2) 1(R)(À)fenchone 295/-À4.9 AE 0.4 phenol À5.3 gas phase [20] [22] /cyclohexane [23] (4) (R)(À)carvone 326/-+ 0.7 AE 0.2 tetramethylcyclohexanone + 0.8 methylcyclohexane [24] , decalin [22] (5) 1(R)4(S)(À)menthone 280/213 À1.3 AE 0.3 methylcyclohexanone À1.6 acetonitrile/water [25] water [17,18] , ethanol [19] (7) S-(À)phenylethylamine 266/-+ 0.65 AE 0.05 phenol + 0.1 water [19]…”

Enantiodivergent Synthesis of (R)- and (S)-Rolipram

“…Although 9b also presents mainly positive CE's in this latter region, it shows a weak negative CE at 251 nm. The effect of substituents on the benzene moiety, can have pronounced effects on the observed CE's [27,28]. The CD spectrum of (S)-phenylethylamine shows a positive CE at the origin of the 1 L b band, λ max 268 (∆ε max +0.11).…”

Effect of intramolecular interactions on circular dichroism of ortho‐substituted 1‐phenethylamines

“…When interpreting the obtained CD spectra we paid attention to the sign and value of the short-wave Cotton effect below 250 nm, as the long-wave CE in the 1 L b aromatic band region is not informative due to its rather small value (sometimes it lies near the zero axis), vibronic character, and unpredictable changes. We cannot correlate CD in this region with structure, as was done for some substituted phenethylamines and phenethylcarbinols 12 : there are no values of spectroscopic moments for most substituents in our ortho-substituted amines.…”