نتایج جستجو برای: diazo coupling
تعداد نتایج: 153420 فیلتر نتایج به سال:
The title benzene hemisolvate, C(17)H(18)N(2)O(3)·0.5C(6)H(6), features an essentially planar (the r.m.s. deviation of the non-H atoms, excluding methyl-C, is 0.071 Å) diazo mol-ecule with an E conformation about the N=N bond, and a half-mol-ecule of benzene disposed about a centre of inversion. The dihedral angle formed between the benzene rings of the diazo mol-ecule is 7.69 (12)°. In the cry...
We report a Lewis acid catalyzed reaction sequence involving a 1,2-shift and subsequent C–H insertion that gives monocyclic and fused bicyclic cyclopentenone products. This reaction sequence, which is initiated by treating b-hydroxy-a-diazo ketones with a Lewis acid, proceeds through vinyl cation intermediates that insert at non-activated gamma C–H bonds. This reaction represents an alternative...
The title compound, C17H24O5, featuring a 2-carbeth-oxy-3-oxepanone unit in its intra-molecularly O-H⋯O hydrogen-bonded enol form, was obtained via [(CF3CO2)2Rh]2-catal-ysed intra-molecular O-H bond insertion in the α-diazo-ω-hy-droxy-β-ketoester, ethyl 4-[(1S,3aS,6R,6aS)-6-hy-droxy-2,2,3a-trimethyl-3-oxo-octa-hydro-penta-len-1-yl]-2-diazo-3-oxobutano-ate. The seven-membered oxacyclic ring, thu...
2-Cyclopenten-1-one-5-carboxylic ester derivatives 14 are synthesized in a four-step-reaction sequence starting from alkynyl aldehydes 9 via 4Z-b-vinyl-a-diazo b-ketoesters intermediate 8. The synthetic method for 8 is described. When the d substituent is an alkyl group, Rh(II)-mediated decomposition of the diazo compounds 8 led to an intramolecular C–H insertion to afford 2-cyclopenten-1-one-5...
We report a Lewis acid catalyzed reaction sequence involving a 1,2-shift and subsequent C-H insertion that gives monocyclic and fused bicyclic cyclopentenone products. This reaction sequence, which is initiated by treating β-hydroxy-α-diazo ketones with a Lewis acid, proceeds through vinyl cation intermediates that insert at non-activated gamma C-H bonds. This reaction represents an alternative...
1,4-Dioxenes present interesting potential as synthetic intermediates and as unusual motifs for incorporation into biologically active compounds. Here, an efficient synthesis of functionalized 1,4-dioxenes is achieved in two steps. Using keto-diazo compounds, a ruthenium catalyzed O-H insertion with β-halohydrins followed by treatment with base results in cyclization with excellent selectivity,...
In the enanti-omerically pure title compound, C(11)H(19)N(3)O(3)S, the chain C-N-C(O)-O-C-C (from the asymmetric carbon to a methyl of the tert-butyl group) displays an extended conformation. In the crystal, mol-ecules are linked into chains parallel to the c axis by classical N-H⋯O(diazo-carbon-yl) hydrogen bonding and an unusual inter-molecular three-centre inter-action involving the amino ac...
In the title compound {systematic name: 5-tert-butyl-3-[2,4-di-chloro-5-(prop-2-yn-yloxy)phen-yl]-1,3,4-oxa-diazol-2(3H)-one}, C15H14Cl2N2O3, which is an oxa-diazo-lone herbicide, the dihedral angle between the planes of the oxa-diazo-lone and benzene rings is 65.84 (6)°. In the crystal, weak inter-molecular Cl⋯Cl [3.3600 (7) Å] short contacts link adjacent mol-ecules, forming chains along the ...
Hemoglobin interferes with determination of total bilirubin by the diazo procedure with the DuPont aca. We compared results by that procedure with those by a manual direct spectrophotometric two-wavelength method. Because the manual method was not inhibited by hemolysis as was the DuPont aca diazo procedure, we reprogrammed our DuPont aca to measure the absorbance of diluted serum samples at 45...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید