6627-83-4Relevant academic research and scientific papers
Controlling olefin isomerization in the heck reaction with neopentyl phosphine ligands
Lauer, Matthew G.,Thompson, Mallory K.,Shaughnessy, Kevin H.
, p. 10837 - 10848 (2015/01/08)
The use of neopentyl phosphine ligands was examined in the coupling of aryl bromides with alkenes. Di-tert-butylneopentylphosphine (DTBNpP) was found to promote Heck couplings with aryl bromides at ambient temperature. In the Heck coupling of cyclic alkenes, the degree of alkene isomerization was found to be controlled by the choice of ligand with DTBNpP promoting isomerization to a much greater extent than trineopentylphosphine (TNpP). Under optimal conditions, DTBNpP provides high selectivity for 2-aryl-2,3-dihydrofuran in the arylation of 2,3-dihydrofuran, whereas TNpP provided high selectivity for the isomeric 2-aryl-2,5-dihydrofuran. A similar complementary product selectivity is seen in the Heck coupling of cyclopentene. Heck coupling of 2-bromophenols or 2-bromoanilides with 2,3-dihydrofurans affords 2,5-epoxybenzoxepin and 2,5-epoxybenzazepins, respectively.
Analysis of β-amino alcohols as inhibitors of the potential anti-tubercular target N-acetyltransferase
Fullam, Elizabeth,Abuhammad, Areej,Wilson, David L.,Anderton, Matthew C.,Davies, Steve G.,Russell, Angela J.,Sim, Edith
supporting information; experimental part, p. 1185 - 1190 (2011/04/16)
The synthesis and inhibitory potencies of a novel series of β-amino alcohols, based on the hit-compound 3-[3′-(4″-cyclopent-2?- en-1?-ylphenoxy)-2′-hydroxypropyl]-5,5 dimethylimidazolidine-2,4- dione as specific inhibitors of mycobacterial N-acetyltransferase (NAT) enzymes are reported. Effects of synthesised compounds on growth of Mycobacterium tuberculosis have been determined.
Photogeneration of o-Quinone Methides from o-Cycloalkenylphenols
Leo, Edgar A.,Delgado, Julio,Domingo, Luis R.,Espinos, Amparo,Miranda, Miguel A.,Tormos, Rosa
, p. 9643 - 9647 (2007/10/03)
6-Alkylidenecyclohexa-2,4-dienones (o-quinone methides II) have been generated by photolysis of 2-(2′-cycloalkenyl)phenols 1 and trapped by methanol to give the ring-opened products 2. The best results have been obtained with the cyclohexenyl derivatives 1a, 1e, and 1f. In the case of the cyclopentenyl derivative 1b, photoproduct 2b was not observed, whereas only small amounts of 2c and 2d were formed from the seven- and eight-membered ring analogues 1c and 1d. Thus, ring size appears to be a key factor in the formation of o-quinone methides. This experimental result has been rationalized by means of density-functional theory (DFT) calculations. On the other hand, phenol substitution also appears to play a role in the process. Thus, electron-withdrawing groups such as CF3 (1f) accelerate the reaction, whereas the opposite is true for electron-donating groups such as OCH 3 (1e). This is explained by an excited-state intramolecular proton transfer (ESIPT) mechanism, as the above results are consistent with the excited-state acidities of the different phenols. The lack of reactivity in the case of ketone 1g, where the intersystem crossing quantum yield is close to unity, allows us to rule out a mechanism involving the triplet state.
Alkylation of phenol with olefins in the presence of lignosulfonic acids
Pisanenko,Smirnov-Zamkov
, p. 1655 - 1657 (2007/10/03)
Alkylation of phenol with cyclohexene, 1-octene, dicyclopentadiene, 1,3-cyclopentadiene, and butylene polymer distillate at 100-140°C was studied. The process was performed in the presence of lignosulfonic acids obtained from industrial calcium lignosulfonates.
Molybdenum(II)-catalyzed allylation of electron-rich aromatics and heteroaromatics
Malkov, Andrei V.,Davis, Stuart L.,Baxendale, Ian R.,Mitchell, William L.,Kocovsky, Pavel
, p. 2751 - 2764 (2007/10/03)
The stable, readily available molybdenum(II) complexes [Mo(CO)4Br2]2 (B) and Mo(CO)3(MeCN)2-(SnCl3)Cl (C) have been found to catalyze C-C bond- forming allylic substitution with electronrich aromatics (e.g., 15 + PhOMe → 62) and heteroaromatics (e.g., 15 + 36 → 88) as nucleophiles under mild conditions (room temperature, 30 min-3 h). Remarkable is the para-selectivity for anisole, whereas phenol tends to favor ortho-substitution in certain instances. Mechanistic and stereochemical experiments are indicative of Lewis-acid catalysis rather than a metal template-controlled process.
IMPROVED PROCEDURES FOR THE PALLADIUM-CATALYZED INTERMOLECULAR ARYLATION OF CYCLIC ALKENES
Larock, Richard C.,Gong, William H.,Baker, Bruce E.
, p. 2603 - 2606 (2007/10/02)
Improved procedures for the palladium-catalyzed, intermolecular, allylic crosscoupling of aryl halides and cyclic alkenes inhibit double-bond isomerization and accommodate many important functional groups.
Selective Indirect Oxidation of Phenol to Hydroquinone and Catechol
Dai, S. H.,Lin, C. Y.,Rao, D. V.,Stuber, F. A.,Carleton, P. S.,Ulrich, Henri
, p. 1722 - 1725 (2007/10/02)
The introduction of a hydroxyl function into phenol to give hydroquinone and catechol can be achieved in high yields by the reaction of hydrogen peroxide with alkenylphenols.These alkenylphenols are obtained by thermolysis of bisphenol A, alkylation of phenol with cyclopentadiene followed by isomerization, and alkylation of phenol with mesityl oxide followed by thermolysis to give 4-isopropenylphenol, 2- and 4-(cyclopenten-1-yl)phenol, and 2,2,4-trimethyl-1,2-chromene, respectively.
