Sequential Au/Cu Catalysis: A Two Catalyst One-Pot Protocol for the Enantioselective Synthesis of Oxazole α-Hydroxy Esters <i>via</i>
Intramolecular Cyclization/Intermolecular Alder-Ene Reaction
作者:Kumara Swamy Nalivela、Matthias Rudolph、Elham S. Baeissa、Basma G. Alhogbi、Ibraheem A. I. Mkhalid、A. Stephen K. Hashmi
DOI:10.1002/adsc.201800246
日期:2018.6.5
alkylglyoxylates 3 was developed. The first step of the one‐pot procedure is the selective intramolecular in situ formation of an alkylideneoxazoline 2, which then in an intermolecular reaction is enantioselectively transformed to the oxazole α‐hydroxy ester derivatives 4 in quantitative yield and good to excellent enantioselectivity via an asymmetric copper(II)‐catalyzed Alder‐ene reaction.
对于恶唑α羟基酯衍生物的对映选择性合成中的方便的方案4从容易得到的propargylamides 1和alkylglyoxylates 3被开发。单锅法的第一步是选择性地在分子内原位形成亚烷基neoxazoline 2,然后在分子间反应中将其以定量产率对映选择性地转化为恶唑α-羟基酯衍生物4,并通过不对称得到良好至优异的对映选择性铜(II)催化的Alder-ene反应。