UNIGE document Scientific Article
previous document  unige:7836  next document
add to browser collection

Asymmetric 1,3-Dipolar Cycloadditions of 2-Diazo-cyclohexane-1,3-diones and Alkyl Diazopyruvate

Chappellet, Sabrina
Published in Helvetica Chimica Acta. 2005, vol. 88, no. 5, p. 1010-1021
Abstract The 1,3-dipolar cycloaddition reactions of 2-diazocyclohexane-1,3-dione (7a; Table 1) and of alkyl diazopyruvates (11a-e; Table 3) to 2,3-dihydrofuran and other enol ethers have been investigated in the presence of chiral transition metal catalysts. With RhII catalysts, the cycloadditions were not enantioselective, but those catalyzed by [RuIICl2(1a)] and [RuIICl2(1b)] proceeded with enantioselectivities of up to 58% and 74% ee, respectively, when diazopyruvates 11 were used as substrates. The phenyliodonium ylide 7c yielded the adduct 8a in lower yield and poorer selectivity than the corresponding diazo precursor 7a (Table 2) upon decomposition with [Ru(pybox)] catalysts. This suggests that ylide decomposition by RuII catalysts, contrary to that of the corresponding diazo precursors, does not lead to Ru-carbene complexes as reactive intermediates. Our method represents the first reproducible, enantioselective 1,3-cycloaddition of these types of substrates.
Full text
Article - document accessible for UNIGE members only Limited access to UNIGE
(ISO format)
MULLER, Paul, CHAPPELLET, Sabrina. Asymmetric 1,3-Dipolar Cycloadditions of 2-Diazo-cyclohexane-1,3-diones and Alkyl Diazopyruvate. In: Helvetica Chimica Acta, 2005, vol. 88, n° 5, p. 1010-1021. https://archive-ouverte.unige.ch/unige:7836

248 hits

0 download


Deposited on : 2010-06-21

Export document
Format :
Citation style :