Judit Horváth

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Chemical reaction-diffusion patterns often serve as prototypes for pattern formation in living systems, but only two isothermal single-phase reaction systems have produced sustained stationary reaction-diffusion patterns so far. We designed an experimental method to search for additional systems on the basis of three steps: (i) generate spatial bistability(More)
In his seminal 1952 paper, Alan Turing predicted that diffusion could spontaneously drive an initially uniform solution of reacting chemicals to develop stable spatially periodic concentration patterns. It took nearly 40 years before the first two unquestionable experimental demonstrations of such reaction-diffusion patterns could be made in isothermal(More)
Teutsch G. and Bélanger A. treated 5alpha,10alpha epoxides with Grignard-reagents catalyzed by copper(I) ions. The reaction with steroidal epoxides proceeded with complete regio- and stereospecificity, leading exclusively to the 11beta-substituted compounds. According to our synthetic strategy, the 5,10 epoxide isomers were not separated; instead, the pure(More)
17-formyl-androst-16-ene and its analogues were synthesized from the corresponding 17-iodo-16-ene derivatives in palladium-catalyzed formylation reaction using tributyltin hydride as hydrogen source under mild reaction conditions. The formation of androst-16-ene and its isomerization products, as well as that of analogous steroidal olefins as side-products,(More)
Homogeneous catalytic hydrazinocarbonylation of some steroid derivatives possessing iodo-alkenyl moiety (17-iodo-androst-16-ene 1, 17-iodo-3-methoxy-estra-1,3,5(10),16-tetraene 2, 17-iodo-4-aza-4-methyl-androst-16-en-3-one 3 and 17-iodo-6beta-hydroxy-3alpha,5alpha-cycloandrost-16-ene 4) were carried out in the presence of a palladium catalyst, a base and(More)
Steroidal dienes were synthesised by Stille-coupling of the corresponding alkenyl iodides with vinyltributyltin under microwave irradiation in a domestic microwave oven in drastically reduced reaction times. Rate acceleration was observed also in the one-pot Stille-coupling-Diels-Alder reaction of 17-iodo-5alpha-androst-16-ene. Stereoselectivity of(More)
Heck reactions of some steroid derivatives possessing iodo-alkenyl moiety (17-iodo-androst-16-ene, 1, 17-iodo-4-aza-4-methyl-androst-16-en-3-one, 2, 17-iodo-4-aza-androst-16-en-3-one, 3) were carried out in the presence of palladium catalysts using various olefins (methyl acrylate, ethyl methacrylate, allyl alcohol and allyl acetate) as coupling partners.(More)
The palladium-catalyzed coupling of various 17-iodo-delta 16 steroids (17-iodo-androst-16-ene, 17-iodo-4-methyl-4-aza-androst-16-en-3-one, and 17-iodo-4-aza-androst-16-en-3-one) with dialkyl phosphites (dimethyl phosphite, diethyl phosphite, and diisopropyl phosphite) was examined in detail. The only successful condition for homogeneous coupling involved(More)
Direct and carbonylative coupling reactions of various steroid derivatives possessing iodo- and bromo-alkenyl moiety (17-iodo-androst-16-ene, 1, 17-bromoandrost-2,16-diene, 2, 17-iodo-4-aza-4-methylandrost-16-en-3-one, 3, 17-iodo-4-azaandrost-16-en-3-one, 4) with vinyltributylstannane and ethynyltributylstannane were carried out in the presence of various(More)
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