Enantioselective Lewis Acid Catalyzed Michael Reactions of Alkylidene Malonates. Catalysis by <i>C</i><sub>2</sub>-Symmetric Bis(oxazoline) Copper(II) Complexes in the Synthesis of Chiral, Differentiated Glutarate Esters
作者:David A. Evans、Tomislav Rovis、Marisa C. Kozlowski、C. Wade Downey、Jason S. Tedrow
DOI:10.1021/ja002246+
日期:2000.9.1
C2-symmetricbis(oxazoline)−Cu(II) complexes 1 catalyze the Mukaiyama Michael reaction of alkylidene malonates and enolsilanes. The use of hexafluoro-2-propanol is essential to induce catalyst turnover. High enantioselectivities are exhibited by bulky alkylidene malonate β-substituents using catalyst 1a. The glutarate ester products are readily decarboxylated to provide chiral 1,5-dicarbonyl synthons
Iron(III) Chloride as a Water-Compatible Lewis Acid for Diastereoselective Aldol Reactions in Water in the Presence of a Surfactant
作者:Naohiro Aoyama、Kei Manabe、Shu Kobayashi
DOI:10.1246/cl.2004.312
日期:2004.3
Diastereoselective aldol reactions of various aldehydes with silicon enolates in water have been successfully carried out using iron(III) chloride and a surfactant. Contrary to previous understandi...
N-Allylideneamines 1a, b were prepared from acrolein and diphenylethyl or trityl amine in the presence of Ti(OEt)4. Double nucleophilicaddition of various ketene silyl (thio)acetals and trimethylsilyl cyanide to these imines proceeded efficiently to give, after workup with TFA, homoglutamic acid derivatives 3 and valerolactam 5.
Asymmetric Electrophilic α-Amination of Silyl Enol Ether Derivatives via the Nitrosocarbonyl Hetero-ene Reaction
作者:David Sandoval、Andrey V. Samoshin、Javier Read de Alaniz
DOI:10.1021/acs.orglett.5b02208
日期:2015.9.18
nitrosocarbonyl hetero-ene reaction is described. The procedure uses a copper-catalyzed aerobic oxidation of a commercially available chiral nitrosocarbonyl precursor (EleNOr) and is operationally simple. The transformation is both high yielding and highly diastereoselective for a range of silyl enol etherderivatives. A variety of synthetically useful postfunctionalization reactions are presented along with