Pyridyl-substituted 1,3,5-triazines were synthesized in good to excellent yields via an unprecedented one-step cyclocondensation of 4H-pyrido[1,3]oxazin-4-ones with amidines at room temperature or under microwave irradiations. The broad applicability was demonstrated by 33 examples with a variety of amidines and three different 4H-pyrido[1,3]oxazin-4-one chemical series. In addition, a one-pot process from 4H-pyrido[1,3]oxazin-4-one precursors (imide sodium salts) was developed and led to the desired triazines compounds, thus allowing a one-step economy in their global synthetic preparation. This approach provides rapid access to pyridyl (or pyridone)-substituted 1,3,5-triazines with high potential in various fields of application.

Site‐selective functionalization of arenes that is complementary to classical aromatic substitution reactions remains a long‐standing quest in organic synthesis. Exploiting the generation of halenium ion through oxidative process and the protonation of the nitrogen containing function in HF/SbF5, the chlorination and iodination of classically inert Csp2−H bonds of aromatic amines occurs. Furthermore, the superacid‐promoted (poly)protonation of the molecules acts as a protection, favoring the late‐stage selective halogenation of natural alkaloids and active pharmaceutical ingredients

Divergent Pd-catalyzed reaction cascades with various 1,3-diynamides yielding either 2-amino-3-alkynylindoles or 2-amino-4-alkenylquinolines were established. Omitting or adding TBAF (tetrabutylammonium fluoride) to the reaction of N,N-(2-iodophenyl)(4-toluenesulfonyl)-1,3diynamides with secondary or primary amines in the presence of KOH in THF and catalytic amounts of Pd(PPh 3 ) 4 completely changed the outcome of the reaction. In the absence of TBAF, 2-amino-3-alkynylindoles were the sole products, while the presence of TBAF switched the product formation to 2-amino-4-alkenylquinolines. Deuterium labeling proceeded selectively at the C3 and C11 positions of the 2-amino-4alkenylquinoline products and this suggests the unprecedented formation of [4]cumulenimines from 1,3-diynamides as reactive key intermediates.

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Divergent Pd‐catalyzed reaction cascades with various 1,3‐diynamides yielding either 2‐amino‐3‐alkynylindoles or 2‐amino‐4‐alkenylquinolines were established. Omitting or adding TBAF (tetrabutylammonium fluoride) to the reaction of N,N‐(2‐iodophenyl)(4‐toluenesulfonyl)‐1,3‐diynamides with secondary or primary amines in the presence of KOH in THF and catalytic amounts of Pd(PPh3)4 completely changed the outcome of the reaction. In the absence of TBAF, 2‐amino‐3‐alkynylindoles were the sole products, while the presence of TBAF switched the product formation to 2‐amino‐4‐alkenylquinolines. Deuterium labeling proceeded selectively at the C3 and C11 positions of the 2‐amino‐4‐alkenylquinoline products and this suggests the unprecedented formation of [4]cumulenimines from 1,3‐diynamides as reactive key intermediates.

Commercially available Fe­(TTP)Cl catalyzes three-component dearomative formal cycloaddition reactions between pyridines, diazo compounds, and coumalates. Diversely substituted annelated seven-membered N-heterocycles could be generated in less than 10 min in one step at room temperature. The reaction is compatible to gram scale. The extension to benzimidazoles in place of pyridines has been successfully demonstrated. The mechanism of this reaction has been carefully examined by computational studies that corroborate the observed regioselectivities.

Access to Pyridyl-Substituted 1,3,5-Triazines from 4H-Pyrido[1,3]oxazin-4-ones via a Cyclocondensation Process. -A broad spectrum of the desired triazine derivatives is available from 4H-pyrido[1,3]oxazin-4-one substrates and amidines (used either as free base or salt) and microwave irradiation is found to be optimal for the procedure. Imide sodium salt precursors such as (XVI) or (XVII) can also be used: In this case, the two-step one-pot approach to the heterocyclic system has a high synthetic potential. -(LE FALHER, L.; BEN AYAD, O.; ZIYARET, O.; MAMONTOV, A.; BOTUHA*, C.; THORIMBERT, S.; SLOWINSKI, F.; J. Org. Chem. 79 (2014) 14, 6579-6589, http://dx.doi.org/10.1021/jo5010668 ; Inst. Parisien Chim. Mol., CNRS, Univ. P. et M. Curie, F-75005 Paris, Fr.; Eng.) -Lehmann 02-169