16648-44-5

The iron(II)-catalyzed domino isomerization of 3-alkyl/aryl-4-arylisoxazoles provides a selective access to a wide range of structurally diverse highly substituted indole-3-carboxylates. The operational simplicity, high atom efficiency, and the use of stable starting materials and an inexpensive and low-toxicity catalyst are some of the attractive features of this tandem double ring-opening-ring-closure strategy.

The disclosed subject matter provides pyrazolone derivative compounds, pharmaceutical compositions comprising such compounds, kits comprising such compounds, and methods of using such compounds or pharmaceutical compositions. In particular, the disclosed subject matter provides methods of using such compounds or pharmaceutical compositions for treating heart failure.

Parallel and practical methods for the preparation of both (E)- and (Z)-β-aryl1-β-aryl2-α,β-unsaturated esters 1 and (E)- and (Z)-α-aryl1-β-aryl2-α,β-unsaturated esters 2 are described. These methods involve accessible, robust, stereocomplementary N-methylimidazole (NMI)-mediated enol tosylations (14 examples, 70-99 % yield), as well as stereoretentive Suzuki-Miyaura cross-couplings (36 examples, 64-99 % yield). The highlighted feature of the present protocol is the use of parallel and stereocomplementary approaches to obtain highly (E)- and (Z)-pure products 1 and 2 by utilizing sequential enol tosylations and cross-coupling reactions. An expeditious and parallel synthesis of (E)- and (Z)-zimelidine (3), which is a highly representative selective serotonin reuptake inhibitor (SSRI), was performed by utilizing the present methods.

Several analogues of strigol, which is a germination stimulant for seeds of the parasitic weeds Striga and Orobanche, have been prepared. Structural modifications are introduced in the vinyl ether part and include: i, analogues containing an endocyclic vinyl ether double bond, using tetronic acids as precursors; ii, geometrical isomerization of the vinyl ether double bond; and iii, analogues containing a methyl substituent on the vinyl ether double bond. During coupling reactions to give compounds belonging to the last-mentioned class, undesired C-alkylation occurs, which can be minimized by choosing the appropriate reaction conditions. Bioassays reveal that the analogues prepared exhibit considerable activity in the stimulation of seed germination of Striga hermonthica and Orobanche crenata.

Thermolysis and photolysis of diazo-1,3-dicarbonyl compounds were investigated as a fuction of methanol concentration.As the methanol concentration decreased, methyl group migration increased concomitant with the suppresion of O-H insertion into methanol, whereas aryl group migration was essentially uanaltered with the methanol concentration.The results are interpreted as indicating that aryl migration occurs directly from the excited state of diazo compounds, but that methyl migration takes place un the singlet carbene in competition with O-H insertion.