Arasambattu K. Mohanakrishnan

Lewis Acid-Mediated Michaelis−Arbuzov Reaction at Room Temperature: A Facile Preparation of Arylmethyl/Heteroarylmethyl Phosphonates

A facile preparation of arylmethyl and heteroarylmethyl phosphonate esters was achieved involving a Lewis acid mediated Michaelis-Arbuzov reaction at room temperature. Interaction of arylmethyl halides/alcohols with triethyl phosphite in the presence of Lewis acid at room temperature afforded phosphonate esters in good yields.

Functionalization Of 3,4-Ethylenedioxythiophene

Syntheses of 3,4-ethylenedioxythiophene-based vinylenes and oligomers are reported.

Study on photoluminescence from tris-(8-hydroxyquinoline)aluminum thin films and influence of light

Tris-(8-hydroxyquinoline)aluminum (Alq3), which is the most widely used material in organic electroluminescent devices, has been synthesized. Alq3 thin films have been deposited on glass and silicon substrates. The influence of light exposure on the optical properties of Alq3 thin films has been studied. It is confirmed that the photoluminescence (PL) of Alq3 thin film originates from its two geometrical isomers, namely, facial and meridional, which result from PL decay analysis (biexponential fit). It is also confirmed that the PL from both the isomers decreases for increasing light exposure time leading to the creation of luminescent quencher in Alq3 thin film.

Synthetic Studies on Indolocarbazoles: Total Synthesis of Staurosporine Aglycon

A synthesis of staurosporine aglycon and its analogs was achieved in a 28-36% overall yield starting from 2-methylindole. The prominent key steps for the synthesis of the indolocarbazole alkaloids involved electrocyclization and nitrene insertion reactions.

Synthesis of 4-substituted-1,2,3,4-tetrahydro-β-carbolines via intramolecular radical cyclisation and Heck reaction

Abstract A convenient method for the synthesis of 4-substituted-β-carbolines from the corresponding N-allylisogramine derivative is reported using intramolecular free radical cyclisation or Heck reaction.

Diels-Alder reaction of 1,3-diarylbenzo[c]furans with thiophene S,S-dioxide/indenone derivatives: a facile preparation of substituted dibenzothiophene S,S-dioxides and fluorenones.

One pot syntheses of substituted dibenzothiophene S,S-dioxides and fluorenones were successfully achieved by Diels-Alder reaction of benzo[c]furans with thiophene S,S-dioxides and indenones, respectively. Photophysical properties of representative seven- and nine-membered dibenzothiophene S,S-dioxide acenes were also reported.

Lewis Acid/Brönsted Acid Mediated Benz-Annulation of Thiophenes and Electron-Rich Arenes

A facile preparation of benz-annulated heterocycles were achieved at rt involving a Lewis acid/Brönsted acid mediated annulation of heterocycles using 2,5-dimethoxytetrahydrofuran as a four-carbon synthon. The benz-/naphth-annulation was found to be successful with electron-rich arenes as well.

Synthesis of annulated arenes and heteroarenes involving Lewis acid-mediated regioselective annulation of unsymmetrical 1,2-(diaryl/diheteroarylmethine)dipivalates.

A ZnBr(2)-mediated regioselective annulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly efficient for the syntheses of anthracene as well as naphtho[b]thiophene analogues.

(2-Methyl-1-phenyl-sulfonyl-1H-indol-3-yl)methanol.

In the title compound, C16H15NO3S, the plane of the phenyl ring forms a dihedral angle of 80.37 (8)° with the indole ring system. The crystal packing is stabilized by weak O—H⋯O hydrogen bonds which link the molecules into infinite chains along the a axis of the crystal.

Unusual Oxidation of 2 (or 3)-Methylindole Derivatives with Active Manganese Dioxide

Abstract Oxidation of 5-methoxy-1-phenylsulfonyl-2-methyl indole-3-aldehyde (3) with active manganese dioxide to the corresponding indole-2,3-dialdehyde (4) and similar reactions are reported.