One‐Pot Two‐Step Double Annulation of N‐Methoxybenzamides with Alkynes and Alkenes: Regioselective Construction of Isoindolo[2,1‐b]isoquinolin‐5(7H)‐ones

Abstract

A one‐pot two‐step double annulation strategy to produce isoindolo[2,1‐b]isoquinolin‐5(7H)‐ones via the reaction of N‐methoxybenzamides with symmetrical/unsymmetrical alkynes and alkenes has been developed, which proceeds through Ru‐catalysed unsymmetrical double annulations using a single DG under single catalytic conditions. Furthermore, we have developed amide‐alkyne regioselective annulations using unsymmetrical internal alkynes having oxygen/nitrogen substituents leading to a single isomer. The developed procedure offers broad substrate scope, tolerates a wide range of functional groups and affords good product yields.

Fluorescent 7-azaindoleN-linked 1,2,3-triazole: synthesis and study of antimicrobial, molecular docking, ADME and DFT properties

“…For the synthesis of 7-azaindole N -linked benzyl 1,2,3-triazole ( 4a–4i ) hybrids as presented in Scheme 1, commercially available 7-azaindole ( 1 ) was subjected to N -propargylation as per the reported procedure, 52 with the help of propargyl bromide in the presence of sodium hydride in dimethylformamide. The as-obtained N -propargyl 7-azaindole, i.e.…”

Rhodium‐Catalyzed C−H Activation/Annulation of Aryl Hydroxamates with Benzothiadiazol‐Containing Acetylenes: Access to Isoquinoline‐Bridged Donor‐Acceptor Luminophores

“…An inspection of the literature data indicates that the Rh(III)‐catalyzed C−H activation/[4+2] annulation of O ‐substituted aryl hydroxamates perfectly occurred with internal aryl acetylenes in majority cases to afford the corresponding isoquinolin‐1(2 H )‐ones. The reactions with unsymmetrically substituted alkynes can be also synthetically useful in terms of regioselectivity, generally placing the aliphatic or less bulky aryl substituents distal to nitrogen [13a,b,14a,d,18] . Thus, at the beginning of our study we checked the reactivity of readily available N ‐(pivaloyloxy)‐benzamides 1 a , b with internal BTD‐containing acetylene 2 a that was specially synthesized by analogy with known literature protocol [19] .…”

Transition Metal‐Catalyzed C−H Activation/Annulation Approaches to Isoindolo[2,1‐b]isoquinolin‐5(7H)‐ones

“…In 2021, Kumar and co‐workers described a one‐pot two‐step Ru(II)‐catalyzed double annulation strategy to produce isoindolo[2,1‐ b ]isoquinolin‐5(7 H )‐ones from N‐methoxybenzamides with symmetrical/unsymmetrical alkynes and alkenes (Scheme 8). [21] This method featured good yields and broad substrate scope, such as various N‐propargylindoles, N‐propargyl‐7‐azaindoles, N‐propargyl pyrrole, propargyl aryl ethers and propargyl aryl amines. However, styrene could not produce the desired product under standard conditions.…”