One-Pot Synthesis of Indolo[2,1-b]quinazoline-6,12-diones under Aerobic Conditions

An efficient approach for the formation of biologically important indolo[2,1-b]quinazoline-6,12-diones in good to moderate yields has been accomplished from 2-haloacetophenones and anthranilamides employing I2/DMSO/CuI under aerobic conditions. This tandem process is believed to proceed via iodination of 2-haloacetophenone followed by Kornblum oxidation and copper-catalyzed intramolecular N-arylation. This method adopts five reactions such as α-halogenation, oxidation, condensation, aromatization and heteroaryl coupling in a single step which makes it as an attractive and useful for the synthesis of indolo[2,1-b]quinazoline-6,12-diones.

Synthesis of 2,5-Disubstituted Oxazoles from Arylacetylenes and α-Amino Acids through an I2/Cu(NO3)2•3H2O-Assisted Domino Sequence

A new strategy has been developed for the synthesis of 2,5-disubstituted oxazoles from easily available arylacetylenes and α-amino acids in the presence of Cu(NO3)2•3H2O and iodine. This reaction ­process involves the I2/Cu(NO3)2•3H2O-assisted transformation of ­arylacetylene to α-iodo acetophenone, Kornblum oxidation to phenylglyoxal, condensation to imine, decarboxylation/annulation/oxidation reaction sequence to approach 2,5-disubstituted oxazoles.

Investigating the effectiveness of classical and eco-friendly approaches for synthesis of dialdehydes from organic dihalides

Monoaldehydes and dialdehydes are parts of millions of compounds and are extremely versatile intermediates. For the synthesis of monoaldehydes, one impressive approach to date, because of its excellent selectivity, high yield and stability towards over-oxidation and over-reduction, is the oxidation of organic monohalides. Numerous monohalides oxidation based methodologies to afford monoaldehydes are disclosed in literature. In this research work, twelve well-known approaches (well-documented for synthesis of monoaldehydes from monohalides) are investigated for their effectiveness towards synthesis of organic dialdehydes from organic dihalides. The classical approaches under investigation include modified Sommelet oxidation, Kröhnke oxidation, sodium periodate-mediated oxidative protocol, manganese dioxide-based oxidative approach, Kornblum oxidation and Hass-Bender oxidation. The eco-friendly approaches under observation include periodic acid-based IL protocol, periodic acid in vanadium pentoxide-mediated IL method, hydrogen peroxide in vanadium pentoxide-based approach, hydrogen peroxide-mediated IL methodology, IBX-assisted IL protocol and bismuth nitrate-promoted IL technique. In this investigation yield, overoxidation, eco-friendliness, cost-effectiveness and recyclability are the main parameters which are under examination. Hopefully, this research will help chemists in carrying out routine operations in organic synthesis and will also be fruitful to select finest synthetic approach, develop further new transformational methodologies and improve current transformational approaches for the synthesis of dialdehydes.

A photoredox catalyzed iminyl radical-triggered C–C bond cleavage/addition/Kornblum oxidation cascade of oxime esters and styrenes: synthesis of ketonitriles

A photoredox-catalyzed iminyl radical-triggered C–C bond cleavage/addition/Kornblum oxidation cascade of cycloketone oxime esters and styrenes in DMSO is described for the first time.

Practical synthesis of 2,3-dimethoxy-5-hydroxymethyl-6-methyl-1,4-benzoquinone

Abstract2,3-dimethoxy-5-hydroxymethyl-6-methyl-1,4-benzoquinone (V) was prepared with a 75 % yield by means of a reaction sequence starting from 2,3,4,5-tetramethoxytoluene via Blanc chloromethylation reaction, Kornblum oxidation, NaBH