The formation of azulene derivatives from 2H-cyclohepta[b]furan-2-one derivatives

Nozoe, Tetsuo; Takase, Kahei; Nakazawa, Tomoo; Fukuda, S.

doi:10.1016/s0040-4020(01)97748-8

Cited by 46 publications

(9 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Elemental analyses (C, H, N) were carried out by Chemisar/Guelph Chemical Laboratories Ltd., ON, Canada or by Micro-Analysis Inc., Wilmington, DE, USA. 2-Amino-1,3-diethoxycarbonylazulene [ 40 ], acetic-formic anhydride [ 41 ], 2-isocyanoazulene ( 1 ) [ 13 ], 2-isocyano-1,3-diethoxycarbonylazulene ( 3 ) [ 20 ], 2-isocyano-1,3-dicyanoazulene ( 5 ) [ 21 ], and [(OC) 5 Cr(2-isocyano-1,3-diethoxycarbonylazulene)] ( 8 ) [ 19 ] were prepared according to the literature procedures. All other reagents were obtained from commercial sources and used as received.…”

Section: Methodsmentioning

confidence: 99%

Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

et al. 2021

View full text Add to dashboard Cite

Isocyanoazulenes (CNAz) constitute a relatively new class of isocyanoarenes that offers rich structural and electronic diversification of the organic isocyanide ligand platform. This article considers a series of 2-isocyano-1,3-X2-azulene ligands (X = H, Me, CO2Et, Br, and CN) and the corresponding zero-valent complexes thereof, [(OC)5Cr(2-isocyano-1,3-X2-azulene)]. Air- and thermally stable, X-ray structurally characterized 2-isocyano-1,3-dimethylazulene may be viewed as a non-benzenoid aromatic congener of 2,6-dimethyphenyl isocyanide (2,6-xylyl isocyanide), a longtime “workhorse” aryl isocyanide ligand in coordination chemistry. Single crystal X-ray crystallographic {Cr–CNAz bond distances}, cyclic voltametric {E1/2(Cr0/1+)}, 13C NMR {δ(13CN), δ(13CO)}, UV-vis {dπ(Cr) ® pπ*(CNAz) Metal-to-Ligand Charge Transfer}, and FTIR {nNºC, nCºO, kCºO} analyses of the [(OC)5Cr(2-isocyano-1,3-X2-azulene)] complexes provided a multifaceted, quantitative assessment of the π-acceptor/σ-donor characteristics of the above five 2-isocyanoazulenes. In particular, the following inverse linear relationships were documented: δ(13COtrans) vs. δ(13CN), δ(13COcis) vs. δ(13CN), and δ(13COtrans) vs. kCºO,trans force constant. Remarkably, the net electron withdrawing capability of the 2-isocyano-1,3-dicyanoazulene ligand rivals those of perfluorinated isocyanides CNC6F5 and CNC2F3.

show abstract

Section: Methodsmentioning

confidence: 99%

Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Synthesis of 1-Cyano-2-N,N-dimethylformamidinylazulenes 2-Amino-1-cyanoazulene (1a) [9] and 2-amino-3-bromo-1-cyanoazulene (1b), which was obtained by bromination of 1a with N-bromosuccinimide, were treated with 3 molar equivalents of N,N-dimethylformamide dimethyl acetal (DMFDMA) for 8 h under reflux in toluene to afford 1-cyano-2-N,N-dimethylformamidinylazulenes (2a, 2b) in 78 and 73% yields respectively (Scheme 1). Because intermediates (2) have two reactive functional groups, cyano and N,N-dimethylformamidinyl groups, at neighboring positions, they seem to be useful building blocks for heterocycle-fused azulenes.…”

Section: Resultsmentioning

confidence: 99%

“…Preparation of 2-Amino-1-bromo-3-cyanoazulene (1b) by Bromination of 2-Amino-1-cyanoazulene (1a) with N-Bromosuccinimide N-bromosuccinimide (106 mg, 0.6 mmol) was added to a solution of 2-amino-1-cyanoazulene (1a) [9] (0.5 mmol) in benzene (20 mL). After stirring for 1 h at rt, cold water (20 mL) was added to the mixture.…”

Section: -N-arylaminoazuleno[21-d]pyrimides 2331mentioning

confidence: 99%

New Synthetic Approach to 4-N-Arylaminoazuleno[2,1-d]pyrimides

Wang

et al. 2009

Synthetic Communications

View full text Add to dashboard Cite

1-Cyano-2-N,N-dimethylformamidinylazulenes as new synthons directed to heterocycle-fused azulenes were obtained by the condensation of 2-amino-1-cyanoazulenes and N,N-dimethylformamide dimethyl acetal (DMFDMA). 1-Cyano-2-N,N-dimethylformamidinylazulene (2a) and 1-bromo-3-cyano-2-N,N-dimethylformamidinylazulene (2b) reacted with anilines (3a-h) to give 4-N-arylaminoazuleno-[2,1-d]pyrimidines in moderate yields. This reaction provides a new procedure for synthesis of pyrimidine-fused azulenes.

show abstract

“…Dichloromethane (CH 2 Cl 2 ) was distilled with calcium hydride to remove water. Tributyl(4-dodecylthiophen-2-yl)stannane, diethyl 2aminoazulene-1,3-dicarboxylate and 2-amino-6-bromo-azulene-1,3dicarboxylic acid diethyl ester (Compound 1) were prepared according to the reported method by Nozoe [62] with minor modifications. [63][64] Compound 2-6 were prepared according to the reported methods.…”

Section: Materials and Instrumentsmentioning

confidence: 99%

Synthesis and Halochromic Properties of 1,2,6‐Tri‐ and 1,2,3,6‐Tetra‐aryl Azulenes

et al. 2021

View full text Add to dashboard Cite

A series of novel 2,6‐functionalized azulene molecules Azu1‐3 with varied fluorene substituents at the 1‐ and 3‐positions of azulene as well as at the 5’‐position of 2‐thiophene group were synthesized. Their electronic absorption and emission spectra at neutral and protonated states were examined. It was found that after functionalization with fluorenyl groups, Azu1‐3 exhibited absorption maxima at 445, 451 to 468 nm, respectively. In contrast, their corresponding protonated species showed much redshifted absorption maxima at 560, 582 to 643 nm, respectively, mainly due to the extension of conjugation length and the large dipole moment along the C2v axis of 2,6‐substituted azulene molecules. Azu1‐3 are non‐fluorescent in their neutral forms, but became emissive in their protonated states. Analysis of absorption and emission spectra shows that substitution of the 1‐ or 3‐position of azulene led to decrease in response to trifluoroacetic acid.

show abstract

The formation of azulene derivatives from 2H-cyclohepta[b]furan-2-one derivatives

Cited by 46 publications

References 6 publications

Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

Tuning π-Acceptor/σ-Donor Ratio of the 2-Isocyanoazulene Ligand: Non-Fluorinated Rival of Pentafluorophenyl Isocyanide and Trifluorovinyl Isocyanide Discovered

New Synthetic Approach to 4-N-Arylaminoazuleno[2,1-d]pyrimides

Synthesis and Halochromic Properties of 1,2,6‐Tri‐ and 1,2,3,6‐Tetra‐aryl Azulenes

Contact Info

Product

Resources

About