- Palladium-catalyzed direct ortho aroylation of 2-phenoxypyridines with aldehydes and catalytic mechanism investigation
-
A direct ortho aroylation of 2-phenoxypyridines with aldehydes leading to aryl ketones by the use of palladium(II) acetate, tert-butyl hydroperoxide, and chlorobenzene as the catalyst, oxidant, and solvent, respectively, is presented. Intra- and intermolecular kinetic isotope effects, radical trapping, and controlled experiments were carried out to support the proposed catalytic mechanism for the reaction. Syntheses of (2-hydroxyphenyl)(phenyl)methanones and 1-hydroxy-9H-fluoren-9-ones directed from ortho-aroylated 2-phenoxypyridines were demonstrated.
- Chu, Jean-Ho,Chen, Shih-Tien,Chiang, Meng-Fan,Wu, Ming-Jung
-
p. 953 - 966
(2015/03/18)
-
- Cu(I)-catalyzed intramolecular cyclizations of substituted 2-iodobenzophenones under thermal and microwave conditions
-
Novel, easy-to-perform and practical intramolecular Cu(I)-catalyzed cyclizations of substituted 2-iodobenzophenones under thermal and microwave conditions are reported. The isolated cyclized products under microwave conditions are obtained with high yields and with short reaction times offering a valuable and reliable alternative to other protocols for the synthesis of fluorene analogues.
- Haggam, Reda A.
-
p. 6488 - 6494
(2013/07/26)
-
- Synthesis of functionalized salicylates by formal [3+3] cyclocondensation of 1,3-bis(silyloxy)buta-1,3-dienes with 3-alkoxy-2-en-1-ones
-
The formal [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3-dienes with 1-aryl-3-ethoxyprop-2-en-1-ones, available by Heck reaction of benzoyl chlorides with ethyl vinyl ether, afforded a variety of 6-arylsalicylates. The reaction of the products with conce
- Mross, Gerson,Ladzik, Simone,Reinke, Helmut,Spannenberg, Anke,Fischer, Christine,Langer, Peter
-
experimental part
p. 2236 - 2248
(2009/12/26)
-
- Synthesis of functionalized biaryls based on a heck cross-coupling-[3+3] cyclization strategy
-
6-Arylsalicylates were regioselectively prepared by formal [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 1-aryl-3-ethoxyprop-2-en-1- ones which are available by Heck reaction of benzoyl chlorides with ethylvinyl ether. In this context, the first [3+3] cyclizations of brominated substrates are reported. Georg Thieme Verlag Stuttgart.
- Mro?, Gerson,Reinke, Helmut,Langer, Peter
-
scheme or table
p. 963 - 966
(2009/04/04)
-
- Mimicking the biological activity of diazobenzo[b]fluorene natural products with electronically tuned diazofluorene analogs
-
Under appropriate electronic modulation, simple diazofluorene analogs recapitulate the DNA cleavage activity of kinamycin D under thiol-based reducing conditions. Achieving DNA cleavage under these reducing conditions is key to anticancer activity, as the most active compound, 1-methoxydiazofluorene, inhibits the proliferation of HeLa cells.
- Zeng, Wei,Eric Ballard,Tkachenko, Alexander G.,Burns, Virginia A.,Feldheim, Daniel L.,Melander, Christian
-
p. 5148 - 5151
(2007/10/03)
-
- Contrasting behaviour in the photosolvolysis of 1- and 2-hydroxy-9-fluorenols in aqueous solution
-
The photosolvolysis of 1- and 2-hydroxy-9-fluorenols 4-6 has been studied in aqueous solution. All of these 9-fluorenols photosolvolyze efficiently in 1:1 H2O-CH3OH, to give the corresponding methyl ether products in high chemical and quantum yields. Whereas the photosolvolysis of the parent 9-fluorenol (2, R = H) is known to proceed via the very short-lived and formally ground-state antiaromatic 9-fluorenyl cation (1, R = H), the photosolvolysis of 1-hydroxy-9-fluorenol (4) proceeds via a much longer-lived (≈5-10 s) fluorenyl quinone methide 9, which is trappable by ethyl vinyl ether via a [4+2] cycloaddition reaction to give a chroman derivative. Interestingly, 2-hydroxy-9-fluorenol (5) photosolvolyzes via a very short-lived intermediate with similar lifetimes as observed for the 9-fluorenyl cation (1, R = H), although a corresponding fluorenyl quinone methide intermediate is accessible for this compound. This study demonstrates that the mechanism of photosolvolysis of these types of compounds can be dramatically altered when an aryl hydroxy group is present.
- Fischer, Maike,Shi, Yijian,Zhao, Bao-Ping,Snieckus, Victor,Wan, Peter
-
p. 868 - 874
(2007/10/03)
-
- Gas-phase Reactions of 2-Benzyl- and 2-Benzoyl-phenoxyl Radicals, and of 2-Phenoxybenzyl Radicals: Examples of New Hydrogen-transfer Processes
-
Generation of the 2-benzylphenoxyl radical 23 or the 2-phenoxybenzyl radical 24 by flash vacuum pyrolysis of the ethers 8 or 9, or the oxalate 19, respectively, leads to fluoren-1-ol 22 together with 2-benzylphenol 7 and a low yield of xanthene 21.Pyrolysis of the para-substituted derivatives 11 and 20 gives an analogous distribution of products, including two isomeric methylxanthenes 28 and 29 formed via the spirodienyl 27.The reactions of the corresponding 2-benzoylphenoxyl radicals give information on the mechanism of these processes.Thus the formation of the fluorenones 37 and 43 provides evidence for the hydrogen-abstraction mechanism (Scheme 4) of fluorene formation.Secondly, a detailed study of the ratios of xanthones 41 and 42 under a variety of pyrolysis conditions suggests that such 6-membered-ring products are formed by sigmatropic shifts in the spirodienyl, rather than direct cyclisation of the phenoxyl or benzoyl radicals.
- Cadogan, J. I. G.,Hutchison, H. Susan,McNab, Hamish
-
p. 385 - 393
(2007/10/02)
-
- AN INTRAMOLECULAR OXENOID OXIDATION
-
Photooxidation of diphenyldiazomethane and 9-diazofluorene leads to the intramolecular oxenoid oxidation products, o-hydroxybenzophenone and 1-hydroxyfluorenone, respectively.
- Kumar, Shailendra,Murray, Robert W.
-
p. 4781 - 4782
(2007/10/02)
-
