Facile Synthesis of Indolizines via 1,3-Dipolar Cycloadditions in [Omim]Br: The Promotion of the Reaction through Noncovalent Interactions

Abstract

Various indolizines are synthesized through one-pot, two-step 1,3-dipolar cycloadditions in recyclable [Omim]Br with high yields and a broad substrate scope. The promotion of noncovalent interactions between ionic liquids and substrates or intermediates on the reaction is discovered on the basis of the results of control and NMR experiments. Moreover, the 3-arylindolizines can also be prepared from low-activity arylmethylpyridinium ylides in the protocol.

Facile synthesis of indolizines using layered double hydroxides@poly(p‐phenylenediamine) as a catalyst with a green tool (neat technology)

“…The powder XRD patterns of LDHs and LDHs@PpPDA are presented in Figure . The XRD patterns of LDHs and LDHs@PpPDA show a series of sharp lines in the regions of 10°, 30° and 40° illustrating the fact that the synthesized polymer samples have high crystallinity and long‐range ordering …”

Ionic-Liquid-Catalyzed Access to CTr: An Antitumor Agent

“…Presumably, 7 could be better stabilized by the second H-bond formed via a 6-membered ring between the HSO 4 – proton and the N atom of 3 . Intercomplex (or trimerization-like) interaction among three units of 7 assembled a supramolecule ( 8 ) via the H-bonds between the C 2 –H in one complex and the Bn-linked O atom in another. − As a precursor intermediate, 8 was computed to be more stable than its variants (Scheme ; Figure b and S4). The HSO 4 – protons of 8 selectively promoted the formation of three covalent bonds between C 3 and C 8 in different complexes, with the ILs released for next catalytic cycle and benzyl alcohol (verified by TLC) liberated to form trispirocyclic intermediate ( 9 ).…”

Hemoglobin‐Catalyzed Synthesis of Indolizines Under Mild Conditions

“…Traditional synthetic routes to indolizines mainly comprise the Scholtz or Chichibabin reactions. More recently, cycloaddition reactions (1,3‐dipolar cycloadditions), intramolecular cyclizations using acetic anhydride, formation of C3–C4 bond, formation of C1–C9 bond, and formation of C8–C9 bond have been reported . However, most of these methods suffer from some drawbacks, such as the formation of conjugate‐acid waste, narrow substrate scope, harsh reaction conditions, need for toxic transition‐metal catalysts and harmful organic solvents.…”