A deconstruction-reconstruction strategy to access 1-naphthol derivatives: application to the synthesis of aristolactam scaffolds

A deconstruction-reconstruction strategy for the synthesis of multisubstituted polycyclic aromatic hydrocarbons (PAHs) is delineated herein. The deconstruction step enables the synthesis of o-cyanomethylaroyl fluorides that are bifunctional substrates holding both a pro-nucleophile and an electrophile. The construction step involves a formal [4 + 2] benzannulation using o-cyanomethylaroyl fluorides and active methylenes. The utility of this synthetic method is also demonstrated by the synthesis of a tetracyclic aristolactam derivative.

A facile synthesis of phthalimides from o-phthalaldehyde and amines via tandem cyclocondensation and α-C-H oxidation by an electrochemical oxygen reduction reaction

Electrochemical synthesis of phthalimides from o-phthalaldehyde and amines via tandem cyclocondensation and α-C-H oxygenation of isoindolinone was achieved. The α-C-H oxidation proceeded with molecular oxygen via an oxygen reduction reaction (ORR) on the cathode under electrochemical conditions. The synthetic utility of this protocol was successfully demonstrated by employing gram-scale synthesis and obtaining bioactive molecules such as thalidomide and 2-(2,6-diisopropylphenyl)-5-hydroxyisoindoline-1,3-dione. Mechanistic studies and control experiments indicate that molecular oxygen provides oxygen atoms for the reaction.

Transition metal-free advanced synthetic approaches for isoindolinones and their fused analogues

The transition metal-free synthetic protocols of isoindolinone and its fused analogues are highlighted in this review since 2007 to 2021.

Utilization of ortho-alkynylarylcarbonyl derivatives for creating structurally diverse chemical compounds

ortho-Alkynylarylcarbonyl compounds, including ketones, aldehydes, carboxylic acids, carboxylate esters and amides, have served as useful building blocks for synthetic chemists to prepare numerous classes of important molecules. Various synthetic conversions starting from ortho-alkynylarylcarbonyl precursors are made possible by their unique and enabling structures embedded with reactive carbonyl and alkyne functional groups. These functional groups can be converted directly and independently to other compounds by several reactions. This review highlights the use of these compounds as common precursors for the divergent synthesis of valuable molecules. Moreover, these ortho-alkynylarylcarbonyl compounds can be decorated with other functional group tethers which can lead to an even greater diversity of molecular scaffolds.

Total synthesis of aristolactam alkaloids via synergistic C-H bond activation and dehydro-Diels-Alder reactions

A concise total synthesis of aristolactam alkaloids by a synergistic combination of C–H bond activation and dehydro-Diels–Alder reactions is described.

A concise total synthesis of aristolactam alkaloids by a synergistic combination of C–H bond activation and dehydro-Diels–Alder reactions is described. To achieve the synthesis two new synthetic methodologies, namely the oxidative cyclization of benzamides with vinyl sulfone leading to 3-methyleneisoindolin-1-ones via a ruthenium-catalyzed C–H bond activation, and a dehydro-Diels–Alder reaction followed by the fluoride ion mediated desulfonylation of 3-methyleneisoindolin-1-ones with benzynes, were developed. The method presented allows the opportunity for the construction of all the rings of aristolactams from easily available starting materials.

KBr/K2S2O8-mediated dibromohydration of N-(2-alkynylaryl)acetamide

A neighbouring acetamino group-participated regioselective dibromohydration of N-(2-alkynylaryl)acetamide is described here for the synthesis of N-(2-(2,2-dibromo-2-arylacetyl)aryl)acetamide.

Synthesis of benzil-o-carboxylate derivatives and isocoumarins through neighboring ester-participating bromocyclizations of o-alkynylbenzoates

Neighboring ester-participating bromocyclizations of o-alkynylbenzoates are developed for the switchable synthesis of benzil-o-carboxylate derivatives and isocoumarins.

Synthesis of 3,3-disubstituted-2,3-dihydroazanaphthoquinones via simultaneous alkyne oxidation and nitrile hydration of ortho-alkynylarenenitriles

Simultaneous activation of alkynes and nitriles in o-alkynylarenenitriles in the presence of Pd(OAc)₂/H₂O/(±)-CSA afforded 3,3-disubstituted-2,3-dihydroazanaphthoquinones in moderate to excellent yields.