Ring-Opening of 4-Isoxazolines: Competitive Formation of Enamino Derivatives and a,b-Enones
摘要:
Ring-opening of 3-substituted 4-isoxazolines, proceeding through the intermediate isoxazolinium salts, follows two competing reaction pathways leading to alpha,beta-enones and enamines respectively. The rearrangement courses can be controlled as a function of substitution pattern and experimental conditions.
CBr<sub>4</sub> as a Halogen Bond Donor Catalyst for the Selective Activation of Benzaldehydes to Synthesize α,β-Unsaturated Ketones
作者:Imran Kazi、Somraj Guha、Govindasamy Sekar
DOI:10.1021/acs.orglett.7b00348
日期:2017.3.3
CBr4 has been employed as a halogen bond donor catalyst for the selective activation of aldehyde, to achieve an efficient solvent- and metal-free C═C bond forming reaction in the presence of strong acid sensitive groups such as methoxy, cyanide, ester, and ketal for the synthesis of α,β-unsaturated ketones. This unique capability of CBr4 to act as a halogen bond donor has been explored and established
Investigation of Substituent Effects on the Selectivity of 4π-Electrocyclization of 1,3-Diarylallylic Cations for the Formation of Highly Substituted Indenes
作者:Chris D. Smith、Gregory Rosocha、Leo Mui、Robert A. Batey
DOI:10.1021/jo100275q
日期:2010.7.16
meta position particularly favor cyclization. There was no obvious correlation of cyclization selectivity with calculated electron densities as has been suggested for electrophilicaromaticsubstitutionreactions. However, the calculated selectivities determined by a gas-phase (B3LYP/6-31G* + ZPVE) comparison of the relative rates of cyclization were in remarkably good agreement with the observed selectivities
Highly Enantioselective Synthesis of Multifunctionalized Dihydrofurans by Copper-Catalyzed Asymmetric [4 + 1] Cycloadditions of α-Benzylidene-β-ketoester with Diazo Compound
Highly efficient synthesis of chiral tetrasubstituted 2,3-dihydrofuran derivatives has been realized by Cu-catalyzed asymmetric [4 + 1] cycloadditions of alpha-benzylidene-beta-ketoester with a diazo compound. Following this methodology, a series of optically active multifunctionalized dihydrofurans were prepared in high yield with up to 96% ee and 99/1 dr.
QUINTEIRO M.; SEOANE C.; SOTO J. L., REV. ROUM. CHIM., 1979, 24, NO 6, 859-864
作者:QUINTEIRO M.、 SEOANE C.、 SOTO J. L.
DOI:——
日期:——
RUBIO, M. J.;SEOANE, C.;SOTO, J. L.;SUSAETA, A., LIEBIGS ANN. CHEM., 1986, N 1, 210-219
作者:RUBIO, M. J.、SEOANE, C.、SOTO, J. L.、SUSAETA, A.