Homoconjugated and Spiro Push-Pull Systems: Cycloadditions of Naphtho- and Anthradiquinones with Electron-Rich Alkynes

We report the synthesis and characterization of three new classes of push-pull chromophores using [2+2]-cycloaddition reactions of electron-rich alkynes and electron-poor alkenes. Previous investigations have focused on the reactions of cyano-substituted electron acceptors. This study demonstrates that cyano-free electron acceptors, naphtho- and anthradiquinones, can also be used to access extended push-pull systems. The effects of the structural changes on the spectroscopic and electronic properties were investigated by UV/vis spectroscopy. Structures were confirmed by X-ray and NMR analysis in solution.


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Garner, Philip; Doğan, Özdemir; Youngs, Wiley; Vance, Kennedy; Protasiewicz, John; Zaniewski, Rebecca (2001-01-01)
Two complementary approaches to substituted pyrrolidines via stereocontrolled 1,3-dipolar cycloaddition reactions of chiral azomethine ylides are described. In one approach, chiral azomethine ylides were generated by thermolysis of aziridine carboxylate sultams and trapped with a variety of dipolarophiles to give good yields of the corresponding cycloadducts. In the second approach, chiral azomethine ylides were generated from glycyl sultams by 'imine tautomerization' and trapped with dipolarophiles to give...
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Araz, Mihrimah; Doğan, Özdemir; Department of Chemistry (2019)
Asymmetric 1,3-Dipolar Cycloaddition (DC) reactions of azomethine ylides are important for the synthesis of pyrrolidines. These reactions may give enantiomerically pure compounds in the presence of a chiral catalyst in a single step. Therefore, many groups have studied this reaction to synthesize aryl-substituted pyrrolidines in enantiomerically rich form. Although the aryl-substituted pyrrolidine synthesis is very common, the studies involving the heteroaryl-substituted pyrrolidines are quite rare. In gene...
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Polystyrene-b-poly(2-vinyl phenacyl pyridinium hexafluorophosphate) (PS-b-PVPP) was synthesized by reacting polystyrene-b-poly(2-vinyl pyridine) prepared by living anionic polymerization with phenacyl bromide followed by counter anion exchange reaction. The ability of PS-b-PVPP to act as a photoinitiator for both free radical and cationic polymerizations is demonstrated. In the free radical polymerization, the initiation step involves the decay of the excited state of the salt with homolytic bond rupture of...
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A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphonate POAP-A Lewis bases formed the aldol products in up to 75% yield and with 65% ee.
YURTSEVER, E; GUNAY, H; UZER, T (1993-07-15)
The unimolecular dissociation of a model triatomic molecule is analyzed. The model, which is loosely based on the radical HO2, shows mostly regular dynamical behavior although it has enough energy to dissociate. By analyzing the progress towards dissociation, we find that dissociation takes place due to concerted and correlated motions as in the Slater theory of unimolecular reactions rather than the steady accumulation of energy in the dissociative mode.
Citation Formats
Ç. Dengiz, “Homoconjugated and Spiro Push-Pull Systems: Cycloadditions of Naphtho- and Anthradiquinones with Electron-Rich Alkynes,” SYNLETT, pp. 1427–1431, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34368.