Photophysical properties and photochemistry of various substituted cinnamates and cinnamic acids for ultraviolet B blocking were investigated experimentally and theoretically. This series includes monohydroxy, -nitro, and -fluoro derivatives. The absorption spectra were satisfactorily reproduced by the direct SAC-CI method with respect to the peak position and intensity. The transition characte...

Sensitised photolyses of ethoxycarbonyl oximes of aromatic and heteroaromatic ketones yielded iminyl radicals, which were characterised by EPR spectroscopy. Iminyls with suitably placed arene or heteroarene acceptors underwent cyclisations yielding phenanthridine-type products from ortho-additions. For benzofuran and benzothiophene acceptors, spiro-cyclisation predominated at low temperatures, ...

A concise and expeditious approach to the total synthesis of broussonone A, a p-quinol natural compound, has been developed. The key features of the synthesis include the Grubbs II catalyst mediated cross metathesis of two aromatic subunits, and a chemoselective oxidative dearomatizationin the presence of two phenol moieties. Especially, optimization associated with the CM reaction of ortho-alk...

Abstract 4-(2-Pyridylazo)resorcinol (PAR) sodium salt reacts with aromatic aldehydes and malononitrile in aqueous ethanol to form 2-amino-4-aryl-5-hydroxy-6-(2-pyridylazo)-4 H -chromene-3-carbonitriles.

In the title compound, C(8)H(8)N(4)O(5), the nitro groups ortho and para to the hydrazone group are twisted by 10.0 (2) and 3.6 (2)°, respectively, relative to the aromatic ring. The structure exhibits an intra-molecular N-H⋯O hydrogen bond between the hydrazide and ortho-nitro groups. There is a strong inter-molecular C=O⋯H-N hydrogen bond, giving rise to chains, and weaker ONO⋯NO(2) [2.944 (2...

The thermal cis-to-trans isomerisation process has been studied for a series of para-, ortho- and polyhydroxy-substituted azobenzenes in different solvents. The kinetics of the thermal back reaction for the p-hydroxy-substituted azobenzenes depend strongly on the nature of the solvent used, with relaxation times ranging from 200-300 milliseconds in ethanol to half an hour in toluene. Otherwise,...

The first enantioselective total synthesis of (+)-coriandrone A and B, two bioactive natural products, has been achieved in 10 steps and 11 steps starting from commercially available methyl 2-hydroxy-4-methoxybenzoate. Key reactions include a Claison rearrangement, a Shi-type epoxidation-cyclization sequence and ortho-metallation of t-butylbenzamides with (S)-(-)-propylene oxide reaction.

Herein, we report a ruthenium‐catalyzed ketone directed ortho‐arylation wherein the addition of bidentate NC‐type ligand, most effectively 2‐(o‐tolyl) pyridine, significantly enhances C‐H arylation reaction. Various aryl‐alkyl ketones, including cyclic, aliphatic, and heterocyclic ones, are competent substrates, arylboronic acid esters were used as aryl sources. However, substitution with OMe C...