Zhenfeng Xi

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A comparative study on the stabilizing ability between C5Me4(SiMe3) (Cp' for short) and amidinate in rare-earth metal complexes is investigated. Cp' is found to dissociate from half-sandwich bis(propiolamidinate) lanthanides via competition with a propiolamidinate, which clearly shows that the coordinative ability of chelate amidinate is stronger than that(More)
Substituted cyclooctatetraenes are a class of interesting and important compounds both theoretically and synthetically. Since Reppe first discovered the Ni-catalyzed tetramerization of ethyne affording cyclooctatetraene in 1948, transition metal mediated synthesis of this type of compounds has become a primary methodology. In this Feature Article, based on(More)
One Si-tethered diyne is coupled in one pot with three molecules of organonitriles promoted by a low-valent zirconocene species. Cleavage of one of the three CN triple bonds and cleavage of the two Si-C bonds take place to afford pyrrolo[3,2-c]pyridine derivatives after hydrolysis.
The one-pot salt-metathesis reaction of ScCl(3), cyclopentadienyl lithium salts, and allylmagnesium chlorides afforded with ease the corresponding base-free half-sandwich scandium di(eta(3)-allyl) complexes [(C(5)Me(4)SiMe(3))Sc(C(3)H(5))(2)] (1 a), [(C(5)Me(5))Sc(C(3)H(5))(2)] (1 b), and [(C(5)Me(5))Sc(2-MeC(3)H(4))(2)] (1 c) in high yields. Reaction of 1(More)
Bis(alkynyl)silanes react with low valent zirconocene species to afford zirconacyclobutene intermediates. These in situ generated reactive organometallic intermediates can react with alkynes, ketones, aldehydes, and isocyanates by means of a novel skeletal rearrangement. When a zirconacyclobutene intermediate was treated with an alkyne, an(More)
Two novel and synthetically useful reaction patterns of organolithium compounds with nitriles are reported to afford pyridine derivatives as the final products. Both 1-lithio-1,3-dienes and 1,4-dilithio-1,3-dienes, which can be easily generated in situ by lithiation of their corresponding iodo compounds, react with nitriles in the presence of HMPA to form(More)
2,6-Diazasemibullvalenes (NSBVs) readily reacted with oxygen under mild conditions, affording Δ(1)-bipyrrolinones via C-N bond cleavage and C-H bond oxidation. Pyrrolino[3,2-b]pyrrolinone derivatives were efficiently generated when NSBVs were treated with N-oxides in the presence of Lewis acids. Δ(1)-Bipyrrolinones thus obtained could be readily transformed(More)
Stable enols were synthesized from the reaction of (1Z,3Z)-1,4-dilithio-1,3-dienes with acid chlorides and structurally characterized by single-crystal X-ray analysis. These stable enols were formed by a novel de-aromatization/Michael addition/re-aromatization domino process.