Non-hydroxylic clathrate hosts of [4 + 2]π cycloadducts of phencyclone and N-arylmaleimides: recognition of aromatic guests

Yoshitake, Yasuyuki; Misaka, Junichi; Setoguchi, Koji; Abe, Masaki; Kawaji, Tomohiro; Eto, Masashi; Harano, Kazunobu

doi:10.1039/b201915a

Cited by 26 publications

(17 citation statements)

References 19 publications

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“…We have sometimes removed complexed solvent from phencyclone adducts simply by repeated co-distillations with CH 2 Cl 2 or CHCl 3 , with a final co-distillation using CDCl 3 if desired to avoid [proton] NMR peaks of the proton-bearing solvents. It should be noted that Harano and co-workers [15][16][17] have published X-ray crystal structures for several of the phencyclone adducts, and their results provide strong support for the structures of the analogs we present here. Addition of a trace of BHT, a free-radical trap, in these preparations is expected to potentially suppress undesired free-radical reactions, such as free-radical additions to the maleimides, free-radical polymerizations of the maleimides, or a free-radical process of oxidative decarbonylation from phencyclone (leading to 9,10-dibenzoylphenanthrene byproduct) [2,18,19].…”

Section: N-[35-bis(trifluoromethyl)phenyl]maleimidesupporting

confidence: 78%

“…equimolar with adduct), consistent with the reported propensity for some phencyclone adducts to form solvates [15][16][17]. We have sometimes removed complexed solvent from phencyclone adducts simply by repeated co-distillations with CH 2 Cl 2 or CHCl 3 , with a final co-distillation using CDCl 3 if desired to avoid [proton] NMR peaks of the proton-bearing solvents.…”

Section: N-[35-bis(trifluoromethyl)phenyl]maleimidesupporting

confidence: 65%

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Multinuclear NMR studies and ab initio structure calculations of hindered phencyclone diels‐alder adducts from symmetrical cyclic dienophiles: Cyclohexene, vinylene carbonate, vinylene trithiocarbonate and two N‐aryl maleimides

Callahan

Ramirez

Rosmarion

et al. 2005

Journal of Heterocyclic Chem

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A series of hindered Diels-Alder adducts have been prepared from phencyclone, 1, with various unusual symmetrical cyclic dienophiles, including cyclohexene, 2a; vinylene carbonate, 2b; vinylene trithiocarbonate, 2c; and the N-aryl maleimides: N- (4-dimethylamino-3,5-dinitrophenyl)maleimide ("Tuppy's maleimide"), 2d; and N- [3,5-bis(trifluoromethyl)phenyl]maleimide, 2e. The highly hindered adducts, 3a-e, respectively, were extensively characterized by one-and two-dimensional NMR methods, observing proton, carbon-13 and fluorine-19. High resolution COSY45 spectra permitted rigorous proton NMR assignments. The 2D heteronuclear C-H chemical shift correlation spectra (HETCOR, XHCORR) were obtained for adducts 3a-d, allowing specific assignments for protonated carbons. Corrections to earlier proton NMR assignments for the vinylene carbonate adduct are given; results of the gated decoupling 13 C NMR experiment for this adduct supported endo adduct stereochemistry. Relative proton chemical shifts for bridgehead phenyls of adduct 3c appeared anomalous relative to other adducts, suggesting possible special anisotropic interactions (with endocyclic sulfur or other anisotropic groups in the product) due to the unusual calculated orientation of the phenyls. The unsubstituted bridgehead phenyls in all adducts were shown to exhibit slow exchange limit (SEL) 1 H and 13 C spectra on the NMR timescales at ambient temperatures (7 tesla) showing slow rotations about the C(sp 3 )-C(aryl sp 2 ) bonds. The rapid rotation of the N-aryl rings of the maleimide adducts was indicated by fast exchange limit spectra, suggesting that ortho substitution of the N-aryl ring may be necessary to slow this rotation to the SEL regime. Ab initio geometry optimizations at the HartreeFock level were carried out for each adduct, with the 6-31G* basis sets. Appreciable geometry differences were seen in calculated structures, and significant NMR chemical shift differences were experimentally observed, depending on the nature of the groups attached to the (Z)-HC=CH moiety of the dienophiles.

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Section: N-[35-bis(trifluoromethyl)phenyl]maleimidesupporting

confidence: 78%

Section: N-[35-bis(trifluoromethyl)phenyl]maleimidesupporting

confidence: 65%

Multinuclear NMR studies and ab initio structure calculations of hindered phencyclone diels‐alder adducts from symmetrical cyclic dienophiles: Cyclohexene, vinylene carbonate, vinylene trithiocarbonate and two N‐aryl maleimides

Callahan

Ramirez

Rosmarion

et al. 2005

Journal of Heterocyclic Chem

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show abstract

“…We did not see NMR spectral evidence for the potential stereoisomer, i.e., the exo adducts, in our isolated products. Recent X-ray studies of some phencyclone adducts have confirmed the endo configuration normally preferred for Diels-Alder adducts [17][18][19].…”

Section: Syntheses and Nmr Interpretationmentioning

confidence: 80%

1H, 13C, and 19F NMR studies of phencyclone adducts of N-(polyhalophenyl)maleimides: evidence for dynamic NMR in maleamic acids

Marshall¹,

Rosmarion²,

Sklyut³

et al. 2004

Journal of Fluorine Chemistry

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“…Diphenylthiophosphinic and diphenylselenophosphinic chlorides were prepared upon heating chlorodiphenylphosphine with selenium at 120°C for 6 h. 1-Phenylpyrrole-2,5-dione 2a was synthesized according to the literature procedures. 5 …”

Section: General Methodsmentioning

confidence: 97%

Chiral thiophosphoramide and selenophosphoramide ligands in the Cu(I)-promoted catalytic enantioselective 1,3-dipolar cycloaddition reactions of azomethine ylides and pyrrole-2,5-dione derivatives

Shi

2007

Tetrahedron: Asymmetry

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Non-hydroxylic clathrate hosts of [4 + 2]π cycloadducts of phencyclone and N-arylmaleimides: recognition of aromatic guests

Cited by 26 publications

References 19 publications

Multinuclear NMR studies and ab initio structure calculations of hindered phencyclone diels‐alder adducts from symmetrical cyclic dienophiles: Cyclohexene, vinylene carbonate, vinylene trithiocarbonate and two N‐aryl maleimides

Multinuclear NMR studies and ab initio structure calculations of hindered phencyclone diels‐alder adducts from symmetrical cyclic dienophiles: Cyclohexene, vinylene carbonate, vinylene trithiocarbonate and two N‐aryl maleimides

1H, 13C, and 19F NMR studies of phencyclone adducts of N-(polyhalophenyl)maleimides: evidence for dynamic NMR in maleamic acids

Chiral thiophosphoramide and selenophosphoramide ligands in the Cu(I)-promoted catalytic enantioselective 1,3-dipolar cycloaddition reactions of azomethine ylides and pyrrole-2,5-dione derivatives

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