Electron-Transfer-Induced Intramolecular Heck Carbonylation Reactions Leading to Benzolactones and Benzolactams

Abstract

A metal-catalyst-free intramolecular Heck carbonylation reaction of benzyl alcohols and benzyl amines with carbon monoxide under heating at 250 °C affords the corresponding benzolactones and benzolactams in good to excellent yields. A hybrid radical/ionic chain mechanism, involving electron transfer from radical anions generated by nucleophilic attack of alcohols or amines on intermediate acyl radicals, is proposed.

Synthesis of 2-Benzyl-3-(2-oxo-2-phenylethyl)isoindolin-1-one Derivatives in Water under Catalyst-Free Conditions

“…5–8 They exhibit diverse biological activities such as antibacterial, 9 anti-Parkinson’s, 10 anti-inflammatory, 11 antipsychotic, 12 antihypertensive, 13 anticancer, 14 and selective NaV1.7 blocking activity. 15 Isoindolin-1-one derivatives, which are nitrogen-containing heterocycles, are utilized as important key intermediates of many useful organic compounds and natural products. Although the methods currently reported in the literature for the synthesis of isoindolin-1-one derivatives have several advantages, there are also disadvantages, such as the need for metal reagents, strong acids or bases, and multiple synthetic steps.…”

“…Although the methods currently reported in the literature for the synthesis of isoindolin-1-one derivatives have several advantages, there are also disadvantages, such as the need for metal reagents, strong acids or bases, and multiple synthetic steps. 14 , 16 17 18 19 20 21 22 23 24 Owing to the high value of isoindolin-1-one derivatives, demand for developing green methods for their synthesis is increasing.…”

“…[1][2][3][4] Because of their unique pharmacological and biological activity, they are widely used in the synthesis of medicines and pesticides. [5][6][7][8] They exhibit diverse biological activities such as antibacterial, [9] antiparkinsonian, [10] antiinflammatory, [11] antipsychotic, [12] antihypertensive, [13] anticancer, [14] and selective NaV1.7 blocking activity [15] . Isoindolin-1one derivatives, which are nitrogen-containing heterocycles, are also used as important key intermediates of many useful organic compounds and natural products.…”

Phosphine-Free Aminocarbonylation Using Pd/DBU Catalyst: Carbonylative Coupling of Aryl Iodides and Amines

“…The first relies on acyl radical intermediates, which have traditionally been generated by chemical initiators. More recently light, , or heat, , could be used to initiate a radical chain reaction. In addition to the total avoidance of transition metals, those types of processes also display great promise due to their cleaner and increased atom-economic approach.…”