Developments in the Synthesis of 1,2-Dihydropyridines

Abstract

This review provides a comprehensive compilation of available literature concerning the synthesis of 1,2-dihydropyridines. The most important recent developments and concepts related to this topic are emphasised.

Organoselenium‐Catalyzed Regioselective C−H Pyridination of 1,3‐Dienes and Alkenes

“…Thed esired products could be efficiently afforded with N-fluoro-2,4,6-trimethylpyridinium tetrafluoroborate ([TMPyF] + [BF 4 ] À )a nd Selectfluor as the co-oxidant. [13,20] Fore xample,w hen 2a was treated with ethyl acrylate,c ycloadduct 9 was formed by the Diels-Alder reaction in 75 %y ield with excellent stereoselectivity (Scheme 5). When pyridinyl 1,3-dienes 7 were utilized as the substrates, products 8 with an ewly formed six-membered ring were obtained in good yields [Eq.…”

Copper(I)-Catalyzed Nucleophilic Addition of Ynamides to Acyl Chlorides and Activated N-Heterocycles

“…While several reports on regioselective 1,2-additions of organometallic species to pyridine and its analogues exist, the nucleophilic attachment of an ynamide moiety has not been accomplished to date. 18 …”

Organoselenium‐Catalyzed Regioselective C−H Pyridination of 1,3‐Dienes and Alkenes

“…Pyridinium salts are an important class of pyridine derivatives [11] with wide applications in materials, [12] and are good precursors for the construction of piperidine frameworks. [13] Therefore,functionalization of pyridine groups with 1,3-dienes is highly valuable.With this in mind, we envisioned that pyridine could serve as an ucleophile to attack as eleniranium ion, resulting in the formation of pyridinium salt as the product. Pyridine could be initially loaded or derived from fluoropyridinium salts.…”

“…[19] Pyridinium salts can be easily converted into multifunctional compounds. [13,20] Fore xample,w hen 2a was treated with ethyl acrylate,c ycloadduct 9 was formed by the Diels-Alder reaction in 75 %y ield with excellent stereoselectivity (Scheme 5). [7a] It could undergo depyridination to give substituted 1,3-diene 10 in high yield with DBU.…”