Highly regio- and stereoselective 1,3-dipolar cycloaddition of stabilised azomethine ylides to 3,3,3-trihalogeno-1-nitropropenes: Synthesis of trihalomethylated spiroindenepyrroli(zi)dines

Understanding the mechanism and regio‐ and stereo selectivity of [3 + 2] cycloaddition reactions between substituted azomethine ylide and 3,3,3‐trifluoro‐1‐nitroprop‐1‐ene, within the molecular electron density theory

“…The experimental results indicate that this 32CA reaction is characterized by a meta regioselectivity, in which the endo approach is more favored than the exo one. 15 The analysis of IRC paths associated to this 32CA reaction indicated that it takes place via a one-step mechanism (see Figure S1).…”

“…This result is in good agreement with the experimental outcome, in which the CA generated from meta-endo approach was obtained as a single isomer. 15 In addition, the relative energies of cycloadducts are very negative, ranging from À52.49(TS-ox) to À57.27 (TS-mx) kcal/mol., accounting for the irreversibility of this 32CA reaction, and indicates that is only under kinetic control.…”

“…They have found that this 32CA reaction is regio-and stereoselective yielding to the formation of the corresponding meta/endo cycloadduct as a major synthon in all reactions. 15 Over the last years, theoretical chemists have attached great importance to the study and analysis of the nature and mechanism of chemical reactions in order to predict the selectivity of molecules before and during the reaction course. An attempt to explain the mechanistic behaviors of organic reactions, since the first appearance of the model proposed by Houk 16 which depends mainly on the interaction between the frontier molecular orbitals (FMO), and lately, the modern Domingo's molecular electron density theory (MEDT), 17 which focuses on the change of electron density during the approach of reactants.…”

Decade Advance of Isatin in Three‐component Reactions

“…Electron‐deficient alkenes like acrylonitrile, [18a] chalcone, [18b] naphthoquinone, [18c] α, β ‐unsaturated ketones, [18d,e] tetraethyl vinyliden‐ ebis(phosphonate), [18f] azirine, [18g] cyclopropenes, [18h] nitroolefins, [18i,k,l] 3‐nitrochromanes [18i] and maleimide [18m] have been reported. Several literature protocols have utilized environmentally friendly solvents like water, [18a] ethyl lactate, [18c] MeOH, [18b,h,m] EtOH [18d,l] or i PrOH [18k] as the reaction media. Products of these methods exhibited diverse biological properties, such as anti‐inflammatory, [18b] anticancer [18h] activity.…”

An Efficient Regioselective Access to (11Z)‐11‐(3‐Aryl‐5,6‐dihydropyrazin‐2(1H)‐ylidene)‐11H‐indeno[1,2‐b]quinoxaline Derivatives via One‐Pot Three‐Component Reaction

“…On the other hand, indenoquinoxaline derivatives have been extensively applied in three‐component reactions for the creation of polycyclic products . Recently, 11 H ‐indeno[1,2‐ b ]quinoxalin‐11‐one derivatives were used as active intermediates in the synthesis of spiro products including spirofuran‐indenoquinoxalines, spiro[benzo[ a ]benz[6,7]chromeno[2,3‐ c ]phenazine] derivatives, spiro‐indenoquinoxaline pyrrolidines, spiro‐indenoquinoxaline pyrrolizidines, spirolactones, and etc …”