Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl

Synthesis of benzouracils and carbamates from chloroacetamides through carbon-carbon bond cleavage

This work introduces a mild reaction-condition approach for the direct C-C bond cleavage of amides, resulting in the formation of benzouracil and carbamate structures. This method leverages a C-C bond cleavage strategy that enables nucleophilic addition to the amide carbonyl, involving a reactive spiro intermediate. A diverse range of chloroacetamides were synthesized and utilized as bifunctional starting materials in this transformation. The proposed strategy has proven to be a powerful tool for synthesizing a wide variety of compounds, achieving yields of up to 88%.

Conversion of aromatic methyl ketones to esters and carboxylic acids using o-phthalaldehyde as an oxidant

Herein we describe a two-step conversion of aromatic methyl ketones to esters and carboxylic acids employing o-phthalaldehyde as an oxidant. In the first step, o-phthalaldehyde oxidizes the methyl group to 1-indanone, which acts as a leaving group in a subsequent regioselective retro-Claisen condensation to form esters and carboxylic acids. The mild oxidation conditions ensure the method is applicable to a broad range of substrates. Additionally, the two-step method is operationally simple and scalable, and can also be performed in a single pot.

AgNOx as Nitrogen Source for [1+1+3] Cycloaddition of Isocyanides with Isocyanates: Selective Synthesis of 1,2,4-Triazoles

A novel [1+1+3] annulation of AgNOx, isocyanides, and isocyanates for the selective synthesis of 1,2,4-triazoles is presented herein. In this transformation, AgNOx and isocyanates are used as nitrogen sources instead of the traditional hydrazine or diazonium reagents. This process also involves N-O/C-H/C═N bond cleavage and the construction of new N-N/C-N bonds with a good substrate scope and functional group tolerance.

Palladium/Iron-Catalyzed Wacker-Type Oxidation of Aliphatic Terminal and Internal Alkenes Using O2

The Wacker-type oxidation of aliphatic terminal alkenes proceeds using a Pd/Fe catalyst system under mild reaction conditions using 1 atm O2 without other additives. The use of 1,2-dimethoxyethane/H2O as a mixed solvent was effective. The slow addition of alkenes is also important for improving product yields. Fe(III) citrate was the most efficient cocatalyst among the iron complexes examined, whereas other complexes such as FeSO4, Fe2(SO4)3, Fe(NO3)3, and Fe2O3 were also operative. This method is also applicable to aliphatic internal alkenes, which are generally difficult to oxidize using conventional Pd/Cu catalyst systems. The gram-scale synthesis and reuse of the Pd catalysts were also demonstrated.