Julolidine derivatives

Fluorescence-based bulk viscosity measurement is one application that advertises itself almost immediately, particularly with julolidine-derived molecular rotors where the quantum yield is widely independent from solvent polarity. Solving (5) for r] and assuming proportionality of quantum yield and emission intensity leads to (13),... 

Further anodic oxidation of the monomethoxylated compound in methanol gives N,N-bis(methoxymethyl)aniline 24, which yields a julolidine derivative 25 upon reaction with two molecules of ethyl vinyl ether. 

Julol— signifies a julolidine derivative, the benzene ring is aiready included ... 

Scheme 15.120 En antioselective synthesis of julolidine derivatives via a chiral acid-catalyzed imine formation, organocatalyzed [4+2] cyclization, and Au-catalyzed hydroamination, followed by reduction.

Gong and coworkers coupled an organocatalyzed sequential Povarov reaction, occurring with high yield and enantioselectivity, to a gold-catalyzed intramolecular hydroamination, affording julolidine derivatives 218 (Scheme 42.50). The authors showed that no gold species is involved in the cycloaddition reaction [108]. 

In 2010, Wang et al. applied the gold(I)/chiral Brpnsted acid relay catalysis to a novel three-component cascade reaction, providing direct access to structurally diverse julolidine derivatives 374 in high optical purity (Scheme 2.99). The phosphoric acid (Se)-catalyzed asymmetric Povarov reaction of 2-(2-propynyl)anihnes 365, (V-vinylcarbamate 8, and aldehydes 3 provided enantioenriched tetrahydroquinoline intermediates 372, which then underwent a hydroamination reaction under the catalysis of a gold complex to give julolidine derivatives with up to >99% ee [133]. 

Bohlmann (207) reported the reaction of /I -dehydroquinolizidine with methyl vinyl ketone and with propargyl aldehyde forming a partially saturated derivative of julolidine 135 and julolidine (136), respectively. Compound 135 can be prepared also by mercuric acetate dehydrogenation of ketone 137, which is formed by condensation of 1-bromoethylquinolizi-dine with ethyl acetoacetate (Scheme 11). 

Various xanthene derivatives, including fluorescein, are also used as laser dyes to cover the spectral region from 500 to 700 nm. A modern example is the julolidine-based dye Rhodamine 101 (6.201), which absorbs at 576 nm and lases at 648 nm [79]. 

Julolidine (3) and benzoquinuclidine (4) can be considered as aniline derivatives with parallel and perpendicular electron lone-pairs, respectively. Relative to N,N-dimethylaniline (5), the simplest tertiary aromatic amine, the n orbital of julolidine is destabilized by 0.20 eV, while that of benzoquinuclidine is destabilized by 0.80 eV42. In the latter compound there is no n/jt conjugation while in the former it has a maximum value and, accordingly, the splitting of the first and the third IP is much smaller (0.70 eV) than in the former (2.55 eV) compound. 

The bathochromic shifts of the tetrahydroquinoline or julolidine couplers, such as in dye (114), are associated with the donor portion of the molecule, and in this case the bathochromic shifts arise due to increased interaction of the nitrogen p-orbital with the ring 7r-orbitals, thereby increasing the electron density associated with the acceptor in the azo dyes (71JCS(B)793). The similar azo dyes derived from lilolidine (115) (74MI11205) absorb at shorter wavelengths and with lower intensities than the analogous julolidine azo dyes (114). 

Dye = benzophenone, isopropyl thioxanthone, merocyanine, etc. Dye/amine/maleimide widi Dye = benzophenone, etc. Dye/amine/diphenyl iodonium salt with Dye = eosin, ketocoumarin, methylene blue, thioxanthene dye, fluorone dye, etc. Dye orate salt/triazine derivative with Dye = cyanine dye, styiylquinolinium dye, etc. Dye/borate salt/alkoxypyridinium salt with Dye = carbocyanine dye, etc. Pl/amine/triazine derivative with Dye = pyrromethene dye. Rose Bengal, etc. Dye/hexabisimidazole derivative (e.g. Cl-HABI)/thiol with PI = styiylnaphtothiazole dye, diethylamino benzophenone, julolidine dye, etc. Dye/amine (or... 

Jacobsen s catalyst 317, 330, 332 Johannsen s catalyst 203 Julia-Colonna epoxidation 111 julolidine 1324 -derivatives 1324... 

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