Copper-catalyzed intermolecular cyclization of nitriles and 2-aminobenzylamine for 3,4-dihydroquinazolines and quinazolines synthesis via cascade coupling and aerobic oxidation

Niacin as a Potent Organocatalyst towards the Synthesis of Quinazolines Using Nitriles as C–N Source

“…On realizing the significance of these N ‐heterocyclic moieties, a large number of reports have appeared over the past decades by addressing the issues of previous reports and for their betterment (Scheme ). [2b], [2c], These chemical transformations were realized using metal catalysts such as Mn, Ni, Cu, Ru, Rh, Ir and Pt utilizing varieties of starting materials. [9a], [9f], [9h], [9i], [9j], In recent times, chemists have also came across the synthesis of quinazolines by utilizing non‐catalytic methods such as DDQ, IBX, PIDA and CsOH mediated reactions.…”

“…[2b], [2c], These chemical transformations were realized using metal catalysts such as Mn, Ni, Cu, Ru, Rh, Ir and Pt utilizing varieties of starting materials. [9a], [9f], [9h], [9i], [9j], In recent times, chemists have also came across the synthesis of quinazolines by utilizing non‐catalytic methods such as DDQ, IBX, PIDA and CsOH mediated reactions. [9c], [9d], [9e], [9g] More interestingly, few reports towards the synthesis of substituted quinazolines are known using the concept of organocatalysis.…”

“…[9a], [9f], [9h], [9i], [9j], In recent times, chemists have also came across the synthesis of quinazolines by utilizing non‐catalytic methods such as DDQ, IBX, PIDA and CsOH mediated reactions. [9c], [9d], [9e], [9g] More interestingly, few reports towards the synthesis of substituted quinazolines are known using the concept of organocatalysis. It is noteworthy that, 2‐aminobenzylamines or 2‐aminobenzyl alcohols are largely explored for synthesis of these structurally unique molecules by employing aldehydes, alkyl alcohols and alkylamines as C1 synthon under metal‐catalyzed, non‐metal‐catalyzed and organocatalyzed reaction conditions.…”

“…It is noteworthy that, 2‐aminobenzylamines or 2‐aminobenzyl alcohols are largely explored for synthesis of these structurally unique molecules by employing aldehydes, alkyl alcohols and alkylamines as C1 synthon under metal‐catalyzed, non‐metal‐catalyzed and organocatalyzed reaction conditions. [2a], [2b], [2c], , The previously reported methods have their significance in obtaining broad range of quinazolines along with certain limitations such as restricted applicability of protocol, harsh reaction conditions and harmful by‐products.…”

“…However, there have been limited number of reports on using nitrile as a source of C–N bond. [9e], [9h], [9i], [9j], [10k], [10p] In most of the cases, nitrile has been used as a C–N bond donor along with 2‐aminobenzyl alcohol under metal‐catalyzed reaction conditions or with 2‐aminobenzylamines as C1 synthon under non‐metal‐catalyzed reaction conditions. There are no reports available pertaining the use of nitrile as a C–N bond donor along with 2‐aminobenzylamines under organocatalyzed reaction conditions.…”