A highlyenantioselectiveMichaeladdition of malonate derivatives to chalcone derivatives catalyzed by an N,N′‐dioxide–ScIII complex was developed, which tolerated a broad range of substrates in moderate to excellent yield with 96–99 % ee. The reaction proceeded well in EtOH or water and could be scaled to grams in good yield with 98 % ee using only 1 mol % ligand L–scandium(III) complex as a catalyst
Solvent-Controlled Oxidative Cyclization for Divergent Synthesis of Highly Functionalized Oxetanes and Cyclopropanes
作者:Yang Ye、Chen Zheng、Renhua Fan
DOI:10.1021/ol9012102
日期:2009.7.16
An efficient solvent-controlled oxidative cyclization of Michael adducts of malonates with chalcones with the combination of iodosobenzene and tetrabutylammonium iodide is reported. Highly functionalized oxetanes and cyclopropanes were divergently synthesized in moderate to excellent yields with high diastereoselectivity.
Chiralbisphosphazides complexed with lithium salts efficiently catalyze the direct enantioselective 1,4-addition of dialkyl malonates to acyclic enones. Spectroscopic studies on the stoichiometry of the bisphosphazide and lithium salt have indicated the formation of a 1:1 species as the active enantioselectivecatalyst. It is suggested that the catalyst generates a complex of the protonated phosphazide
Base-Controlled Selective Conversion of Michael Adducts of Malonates with Enones in the Presence of Iodine
作者:Chun-Bao Miao、Min Zhang、Zong-Yong Tian、Hai-Tao Xi、Xiao-Qiang Sun、Hai-Tao Yang
DOI:10.1021/jo201879t
日期:2011.12.2
An efficient base-controlled selective conversion of the Michael adducts of malonates with enones in the presence of iodine is reported. Highly functionalized cyclopropane, oxetane, and α-hydroxylmalonate derivatives are obtained selectively using DBU, Na2CO3, and NaOAc as the base, respectively. O2 was identified to be crucial to the formation of oxetane and α-hydroxylmalonate derivatives.
据报道在碘存在下,丙二酸酯的迈克尔加成物与烯酮的有效的碱控制的选择性转化。分别使用DBU,Na 2 CO 3和NaOAc作为碱分别选择性地获得高度官能化的环丙烷,氧杂环丁烷和α-羟基丙二酸酯衍生物。O 2被确定对于氧杂环丁烷和α-羟基丙二酸酯衍生物的形成至关重要。