Clean and molecularly programmable protocol for preparation of bis-heterobiarylic systems via a domino pseudocyclic reaction as a valuable alternative for TM-catalyzed cross-couplings

Understanding the molecular mechanism of γ‐elimination of nitrous acid in the framework of the molecular electron density theory

“…At the same time the entropy of the molecular system is changed only a slight degree. This is typical of the elimination reactions realized via cyclic/pseudocyclic TSs 8,10,11,21. Within considered TS, intermolecular distances C1 N6 (Δr ≈ 0.5 Å) and O3 H4 (Δr ≈ 0.6 Å) are substantially longer in relation to the starting molecule 1a.…”

“…36 The global electron density transfer (GEDT) 27 to the BET. 34 For the BET studies, the corresponding reaction paths F I G U R E 1 Examples of beta-elimination of nitrous acid 4,5,[7][8][9][10][11] F I G U R E 2 A theoretically possible mechanism for the nitrous acid extrusion from furoxane functionalized nitrolic acids were followed by performing the topological analysis of the ELF for at least 181 nuclear configurations along the IRC paths. The ELF molecular geometries and basin attractor positions were visualized using the GaussView program.…”

“…This reaction opens a possibility for the synthesis of a wide range of three atom components, which are universal precursors for the preparation of five-membered heterocyclic systems. 11,16,17 The molecular mechanism of this type of γ-dehydronitration transformations is however completely unknown. In the older literature, for thermal elimination reactions, the "pericyclic," one-step mechanism was proposed.…”

“…Most of these reactions proceed according to the β‐elimination scheme. The molecular mechanism of this type of decompositions reactions has recently been a subject of systematic studies regarding β‐nitroalkyl sulfoxides, 7,8 β‐nitroalkyl carboxylates, 9 5‐nitroisoxazolidines, 10 Δ 2 ‐4‐nitroisoxazolines 11 as well as 3‐nitro‐2H‐chromene systems, 4,5 and other (Figure 1).…”

Experimental and Theoretical Mechanistic Study on the Thermal Decomposition of 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline

“…This work is a continuation of our comprehensive theoretical and experimental studies about mechanisms of elimination reactions involving different type of nitro-compounds [ 1 , 2 , 3 , 4 , 5 , 6 ]. Recently [ 1 ], we have established, that the [3 + 2] cycloaddition reaction between diphenyldiazomethane 1 and ( E )-3,3,3-trichloro-1-nitroprop-1-ene 2 , can be carried out at room temperature and gives 3,3-diphenyl-4-(dichloromethylene)-5-nitropyrazoline 4 ( Scheme 1 ) as a rare example of methylene functionalised pyrazole derivatives.…”