106584-13-8Relevant articles and documents
Rhodium-Catalyzed ortho-Selective Carbene C-H Insertion of Unprotected Phenols Directed by a Transient Oxonium Ylide Intermediate
Guo, Rui-Ting,Zhang, Ya-Lin,Tian, Jun-Jie,Zhu, Ke-Yu,Wang, Xiao-Chen
, p. 908 - 913 (2020)
ortho-Selective carbene C-H insertion of unprotected phenols is achieved with dimethyl diazomalonate under the catalysis of [Rh(COD)Cl]2. After the C-H insertion, subsequent cyclization and electrophilic addition of another carbene molecule affords tris-carboxylate-substituted 2-benzofuranones as the final reaction products. The enantioselective variant has been developed with the use of chiral diene ligands. Mechanistic experiments indicate that a transient oxonium ylide directing group might be responsible for the regiocontrol at the C-H activation step.
Cu-Catalyzed Dehydrogenative C-O Cyclization for the Synthesis of Furan-Fused Thienoacenes
Mitsudo, Koichi,Kobashi, Yoshiaki,Nakata, Kaito,Kurimoto, Yuji,Sato, Eisuke,Mandai, Hiroki,Suga, Seiji
supporting information, p. 4322 - 4326 (2021/06/21)
The first Cu-catalyzed dehydrogenative C-O cyclization for the synthesis of furan-fused thienoacenes is described. A variety of heteroacenes including a thieno[3,2-b]furan or a thieno[2,3-b]furan skeleton were synthesized by intramolecular C-H/O-H coupling. The use of a mixed solvent of N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, and toluene was essential for suppressing side reactions and efficiently promoting the reaction. Double C-O cyclization was also conducted to afford highly π-expanded furan-fused thienoacenes.
Synthesis of biaryls via intramolecular free radical ipso-substitution reactions
Ujjainwalla, Feroze,Da Mata, Maria Lucília E.N.,Pennell, Andrew M.K.,Escolano, Carmen,Motherwell, William B.,Vázquez, Santiago
, p. 6701 - 6719 (2015/08/24)
A variety of functionalised biaryls and heterobiaryls are prepared by intramolecular free radical [1,5]-ipso-substitution using sulfonamide and sulfonate derived tethering chains. The overall efficiency of the process is determined by appropriately positioned substituents on the aromatic acceptor ring. The extension of the process to benzylic sulfonates and their corresponding N-methylsulfonamide alternatives as substrates in potential [1,6]-ipso-substitution reactions leads mainly to the alternative [1,7] addition products.
Directed ortho borylation of phenol derivatives catalyzed by a silica-supported iridium complex
Yamazaki, Kenji,Kawamorita, Soichiro,Ohmiya, Hirohisa,Sawamura, Masaya
supporting information; experimental part, p. 3978 - 3981 (2010/10/21)
The directed ortho borylation of phenol derivatives protected with an N,N-diethylcarbamoyl group was efficiently catalyzed by an immobilized monophosphine-Ir system, which was prepared in situ from [Ir(OMe)(cod)] 2 and a silica-supported, compact phosphine. The utility of the carbamoyloxy group as a leaving group for metal-catalyzed cross-coupling reactions was demonstrated by its utilization in the synthesis of a terphenyl derivative.
Dioxygenase-catalysed oxidation of monosubstituted thiophenes: sulfoxidation versus dihydrodiol formation.
Boyd, Derek R,Sharma, Narain D,Gunaratne, Nimal,Haughey, Simon A,Kennedy, Martina A,Malone, John F,Allen, Christopher C,Dalton, Howard
, p. 984 - 994 (2007/10/03)
Toluene dioxygenase (TDO)-catalysed sulfoxidation, using Pseudomonas putida UV4, was observed for the thiophene substrates 1A-1N. The unstable thiophene oxide metabolites, 6A-6G, 6K-6N, spontaneously dimerised yielding the corresponding racemic disulfoxide cycloadducts 7A-7G, 7K-7N. Dimeric or crossed [4 + 2] cycloaddition products, derived from the thiophene oxide intermediates 6A and 6D or 6B and 6D, were found when mixtures of thiophene substrates 1A and 1D or 1B and 1D were biotransformed. The thiophene sulfoxide metabolite 6B was also trapped as cycloadducts 17 or 18 using stable dienophiles. Preferential dioxygenase-catalysed oxidation of the substituent on the thiophene ring, including exocyclic sulfoxidation (1H-1J) and cis-dihydroxylation of a phenyl substituent (1G and 1N), was also observed. An enzyme-catalysed deoxygenation of a sulfoxide in P. putida UV4 was noticed when racemic disulfoxide cyclo-adducts 7A, 7B and 7K were converted to the corresponding enantioenriched monosulfoxides 8A, 8B and 8K via a kinetic resolution process. The parent thiophene 1A and the 3-substituted thiophenes 1K-1N were also found to undergo ring dihydroxylation yielding the cis/trans-dihydrodiol metabolites 9A and 9K-9N. Evidence is provided for a dehydrogenase-catalysed desaturation of a heterocyclic dihydrodiol (9Kcis/9Ktrans) to yield the corresponding 2,3-dihydroxythiophene (24) as its preferred thiolactone tautomer (23). A simple model to allow prediction of the structure of metabolites, formed from TDO-catalysed bacterial oxidation of thiophene substrates 1, is presented.
α1-Adrenoceptor agonists: The identification of novel α1A subtype selective 2′-heteroaryl-2-(phenoxymethyl)imidazolines
Bishop, Michael J.,Barvian, Kevin A.,Berman, Judd,Bigham, Eric C.,Garrison, Deanna T.,Gobel, Michael J.,Hodson, Stephen J.,Irving, Paul E.,Liacos, James A.,Navas, Iii, Frank,Saussy Jr., David L.,Speake, Jason D.
, p. 471 - 475 (2007/10/03)
Novel 2′-heteroaryl-2-(phenoxymethyl)imidazolines have been identified as potent agonists of the cloned human α1-adrenoceptors in vitro. The nature of the 2′-heteroaryl group can have significant effects on the potency, efficacy, and subtype selectivity in this series. α1A Subtype selective agonists have been identified.
Chromium- and tungsten-triggered valence isomerism of cis-1-acyl-2-ethynylcyclopropanes via [3,3] sigmatropy of (2-acylcyclopropyl)vinylidene - Metal intermediates
Ohe, Kouichi,Yokoi, Tomomi,Miki, Koji,Nishino, Fumiaki,Uemura, Sakae
, p. 526 - 527 (2007/10/03)
The reaction of cis vicinal acetylethynylcyclopropanes 1 with a catalytic amount of M(CO)5(THF) (M = Cr or W) in the presence of Et3N at room temperature gave ortho-substituted phenols 7 in good yields as valence isomerized products. In the absence of Et3N the reactions did not work at all. The reaction of a cyclopropane having an ester or an amide instead of an acetyl moiety with M(CO)5(THF) did not take place, whereas an ethynylvinylcyclopropane gave a mixture of 1- and 2-substituted 1,3,5-cycloheptatrienes. These valence isomerization reactions are assumed to proceed via the formation of vinylidene-metal intermediates 2 from terminal alkynyl moieties followed by [3,3]sigmatropy of 2 to give seven-membered carbene complexes 3. Copyright
Steric and electronic effects in the synthesis of biaryls and their heterocyclic congeners using intramolecular free radical [1,5] ipso substitution reactions
Da Mata, Maria Lucilia E.N.,Motherwell, William B.,Ujjainwalla, Feroze
, p. 137 - 140 (2007/10/03)
Hindered biaryls and heterobiaryls are even easier to prepare by intramolecular free radical [1,5] ipso substitution using sulfonamide and sulfonate tethering chains, since the introduction of either electron releasing or electron withdrawing groups ortho
REARRANGEMENT OF 2-HETARYLALKYLPYRIDINIUM SALTS
Rumyantsev, A. N.,Terenin, V. I.,Yudin, L. G.
, p. 300 - 303 (2007/10/02)
The rearrangement of 2-thienyl- and 2-furylalkylpyridinium salts to the corresponding anilines by the action of methylammonium sulfites has been studied.It has been shown that the rearrangement of these salts is accompanied in many cases by the formation of phenols and dealkylation products.The influence of the length of the alkyl chain between the heterocyclic rings on the ratio of the rearrangement products has been investigated.
The Synthesis of Hydroxyphenylthiophenes
Baldwin, Larry J.,Pakray, Sudabeh,Castle, Raymond N.,Lee, Milton L.
, p. 1667 - 1669 (2007/10/02)
The synthesis of the five isomeric methoxyphenylthiophenes is described.The methoxy compounds were hydrolyzed to yield the hydroxyphenylthiophenes.
