Regio- and Diastereoselective Dimerization of Diazo Carbonyls: A Cooperative Catalytic Approach to Complex Scaffolds with Four Contiguous Stereocenters
Starting from readily available o-diazoacyl-substituted arene carboxylates, scaffolds with the 5,9-epoxycyclohepta[b]pyran-2(3H)-one core were obtained by cooperative RhII, Lewis and Br?nsted acid catalysis. Four new bonds, three functional gro
Petzold, Martin,Günther, Andre,Jones, Peter G.,Werz, Daniel B.
A Rh(II)-catalyzed cycloaddition approach toward the synthesis of komaroviquinone
Using a rhodium(II)-catalyzed cyclization/cycloaddition sequence as the key reaction step, the icetexane core of komaroviquinone was constructed by an intramolecular dipolar-cycloaddition of a carbonyl ylide dipole across a tethered π-bond. The ylide was arrived at by cyclization of a rhodium carbenoid intermediate onto a proximal ester group. Efforts toward the preparation of the required precursor for elaboration to the natural product are discussed.
Efficient construction of the oxatricyclo[6.3.1.00,0]dodecane core of komaroviquinone using a cyclization/cycloaddition cascade of a rhodium carbenoid intermediate
(Chemical Equation Presented) The rhodium(II)-catalyzed cyclization/cycloaddition cascade of a o-carbomethoxyaryl diazo dione is described as a potential route to the oxatricyclo[6.3.1.00.0]dodecane substructure of the icetexane diterpene komar
Ruthenium(II) porphyrin catalyzed tandem carbonyl ylide formation and 1,3-dipolar cycloaddition reactions of α-diazo ketones
equation presented The ruthenium porphyrin-catalyzed reactions of diazo ketones with π-unsaturated compounds via carbonyl ylide formation/cycloaddition cascade exhibit product yields and selectivities comparable to the analogous reactions with dirhodium c
Zhou, Cong-Ying,Yu, Wing-Yiu,Che, Chi-Ming
p. 3235 - 3238
(2007/10/03)
INTRAMOLECULAR ACID-CATALYZED REACTIONS OF o-CARBOMETHOXY-ω-DIAZOACETOPHENONES
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Chapyshev, S. V.,Kurkovskii, L. I.,Kartsev, V. G.
p. 765 - 770
(2007/10/02)
SYNTHESES OF 4-HYDROXYMETHYL-1(2H)-PHTALAZINONE AND ITS ANALOGS.
4-Hydroxymethyl-1(2H)-phthalazinone (2) was preferably prepared by reduction of 4-ethoxycarbonyl-1(2H)-phtalazinone with NaBH4 in EtOH in good yield.The synthetic method was applicable for the preparation of 7-ethoxycarbonyl-4-hydroxymethyl-1(2H)-phthalazinone and its 2-phenyl derivative, where the regioselective reduction of the ester at the position 4 was possible, leaving the ester at the position 7 intact.The Grignard reaction of 4-ethoxycarbonyl-1(2H)-phthalazinone was also described.
Ishikawa, Masayuki,Eguchi, Yukuo
p. 25 - 30
(2007/10/02)
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