THE THERMAL CYCLIZATION OF 8-(2,2-DISUBSTITUTED VINYL) HEPTAFULVENES LEADING TO AZULENE DERIVATIVES

1972 ◽  
Vol 1 (3) ◽  
pp. 185-188 ◽  
Author(s):  
Haruki Tsuruta ◽  
Takekatsu Sugiyama ◽  
Toshio Mukai
Keyword(s):  
Thermal Cyclization

The Contribution of Ligand Flexibility to Metal Center Geometry Modulated Thermal Cyclization of Conjugated Pyridine and Quinoline Metalloenediynes of Copper(I) and Copper(II)

2001 ◽  
Vol 40 (8) ◽  
pp. 1846-1857 ◽  
Author(s):  
Diwan S. Rawat ◽  
Pedro J. Benites ◽  
Christopher D. Incarvito ◽  
Arnold L. Rheingold ◽  
Jeffrey M. Zaleski
Keyword(s):  
Metal Center ◽  
Thermal Cyclization

scholarly journals Solving the puzzling competition of the thermal C2–C6 vs Myers–Saito cyclization of enyne-carbodiimides

2016 ◽  
Vol 12 ◽  
pp. 43-49 ◽  
Author(s):  
Anup Rana ◽  
Mehmet Emin Cinar ◽  
Debabrata Samanta ◽  
Michael Schmittel
Keyword(s):  
Hydrogen Transfer ◽  
Dft Method ◽  
Thermal Cyclization ◽  
Trapping Reactions

The mechanism of the thermal cyclization of enyne-carbodiimides 7a–c has been studied computationally by applying the DFT method. The results indicate that enyne-carbodiimides preferentially follow the C2–C6 (Schmittel) cyclization pathway in a concerted fashion although the Myers–Saito diradical formation is kinetically preferred. The experimentally verified preference of the C2–C6 over the Myers–Saito pathway is guided by the inability of the Myers–Saito diradical to kinetically compete in the rate-determining trapping reactions, either inter- or intramolecular, with the concerted C2–C6 cyclization. As demonstrated with enyne-carbodiimide 11, the Myers–Saito channel can be made the preferred pathway if the trapping reaction by hydrogen transfer is no more rate determining.

A Novel Photosensitive Polyimide: A Polyimide Containing the Hydroxytriphenylamine Structure with Diazonaphthoquinone

2000 ◽  
Vol 12 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Satoshi Akimoto ◽  
Mitsutoshi Jikei ◽  
Masa-aki Kakimoto
Keyword(s):  
Aqueous Solution ◽  
Phthalic Anhydride ◽  
Ring Opening ◽  
Polyimide Film ◽  
Tetramethylammonium Hydroxide ◽  
Thermal Cyclization

A novel photosensitive polyimide based on a polyimide containing the hydroxytriphenylamine structure (HTA-PI) and 2, 3, 4-tris[1-oxo-2-diazonaphthoquinone-4-sulfonyloxy] benzophenone (D4SB) as a photoreactive compound has been developed. The HTAPI was prepared by the ring-opening polyaddition of 4, 4′-hexafluoroisopropylidenebis(phthalic anhydride) (6FDA) and 4,4′-diamino-4″-hydroxytriphenylamine (DHTA), followed by thermal cyclization in refluxing N-methyl-2-pyrrolidone (NMP). The resulting polyimide film showed excellent transparency to 436 nm light. Photosensitive polyimide containing 30 wt% of D4SB showed a sensitivity of 800 mJ cm−2 and a contrast of 0.8 when it was exposed to 436 nm light followed by development with 5% tetramethylammonium hydroxide (TMAH) aqueous solution at 45°C.

Thermal Cyclization of 2-Acyl-1-azido-3-phenalenones to Phenaleno[1,2-c]isoxazol-7-ones

1998 ◽  
Vol 35 (4) ◽  
pp. 943-947 ◽  
Author(s):  
Wolfgang Stadlbauer ◽  
Michaela Fischer
Keyword(s):  
Thermal Cyclization

scholarly journals A general strategy for visible-light decaging based on the quinone cis-alkenyl lock

2019 ◽  
Vol 55 (34) ◽  
pp. 4965-4968 ◽  
Author(s):  
David P. Walton ◽  
Dennis A. Dougherty
Keyword(s):  
Visible Light ◽  
Protecting Groups ◽  
General Strategy ◽  
Thermal Cyclization ◽  
Coumaric Acid ◽  
Photoremovable Protecting Groups

Combining the fast thermal cyclization of o-coumaric acid derivatives with the intramolecular photoreduction of quinones gives new visible-light photoremovable protecting groups absorbing well above 450 nm.

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