Catalytic [3 + 3]-Cycloaddition for Regioselective Preparation of Tricyclic Oxadiazines

Abstract

Agrochemically useful and structurally important, functionally rich tricyclic-oxadiazines were synthesized in very good yields with excellent diastereoselectivities through a catalytic [3 + 3]-cycloaddition from the readily available p-quinols, azomethine imines, and a catalytic amount of Brønsted base (KOtBu).

Molecular Complexity from Aromatics: Recent Advances in the Chemistry of paraQuinol and Masked para‐Quinone Monoketal

“…The method was found to be highly diastereoselective and chemoselective (Scheme 32). [93] A novel one-pot method was developed under green chemistry condition for the synthesis of morphan derivative 301 by regioselective double Michael addition to quinone monoketal 299 and heterocyclic ketene aminal 300. Water was used as a solvent.…”

[3+3] Cycloaddition of Azomethine Imine: Synthesis of Bi‐ or Tricyclic N‐Heterocycle

“…Et 2 O at 40°C with 84% yield. [12] Probable mechanism of the [3 + 3] cycloaddition reaction describes in Scheme 3. p-quinols (4-alkyl-4-hydroxy-2,5 cyclohexadienones) and their derivatives have vast biological activity and are used in reaction enginnering as well as a precursor to synthesis various natural products such as cleroindicins C, D, and F. [13] A convenient method for the synthesis of agrochemically useful and structurally important, tricyclic-oxadiazines (12) via [3 + 3] cycloaddition reaction of readily available p-quinols (11) and azomethine imines (2) was first developed by Prabhakar Reddy et al(Scheme 4) [14] using Brønsted base (KO t Bu) as a catalyst in DCM solvent with 70% yield and 17 : 1 diasteriomeric ratio in 1 h.…”

“…Catalytic [3 + 3]-cycloaddition for regioselective preparation of tricyclic oxadiazines. [14] Figure 1. Biologically active pyridopyridazine derivatives.…”

“…A convenient method for the synthesis of agrochemically useful and structurally important, tricyclic‐oxadiazines ( 12 ) via [3+3] cycloaddition reaction of readily available p ‐quinols ( 11 ) and azomethine imines ( 2 ) was first developed by Prabhakar Reddy et al . (Scheme ) using Brønsted base (KO t Bu) as a catalyst in DCM solvent with 70% yield and 17 : 1 diasteriomeric ratio in h.…”

Sc(OTf)3-Catalyzed Formal [3 + 3] Cycloaddition Reaction of Diaziridines and Quinones for the Synthesis of Benzo[e][1,3,4]oxadiazines

“…In contrast, much less has been done for heterocycles containing two or more heteroatoms due to the limited availability of appropriate substances to provide two or more heteroatoms in one operation . The synthesis of oxadiazinanes has only been sporadically reported . In particular, a catalytic methods to access 1,3,4-oxadiazinanes remains elusive to our knowledge.…”