6230-80-4Relevant academic research and scientific papers
Catalyst-Controlled Chemodivergent Reactions of 2-Pyrrolyl-α-diazo-β-ketoesters and Enol Ethers: Synthesis of 1,2-Dihydrofuran Acetals and Highly Substituted Indoles
France, Stefan,Guerra Faura, Gabriel,Nguyen, Tena
supporting information, p. 10088 - 10104 (2021/07/31)
A catalyst-controlled, chemodivergent reaction of pyrrolyl-α-diazo-β-ketoesters with enol ethers is reported. While Cu(II) catalysts selectively promoted a [3 + 2] cycloaddition to provide pyrrolyl-substituted 2,3-dihydrofuran (DHF) acetals, dimeric Rh(II) catalysts afforded 6-hydroxyindole-7-carboxylates via an unreported [4 + 2] benzannulation. The choice of enol ether proved to be crucial in determining both regioselectivity and yield of the respective products (up to 91% yield for Cu(II) and 82% for Rh(II) catalysis). Furthermore, the DHF acetals were shown to serve as precursors to 7-hydroxyindole-6-carboxylates (isomeric to the indoles formed from Rh) and highly substituted furans in the presence of Lewis acids. Thus, from a common pyrrolyl-α-diazo-β-ketoester, up to three unique heterocyclic scaffolds can be achieved based on catalyst selection.
Palladium-Catalyzed Cross-Coupling Reaction of α-Heterosubstituted Alkenylmetals. A Stereoselective Route to Heterosubstituted Dienes Suitable for the Diels-Alder Reaction
Negishi, Ei-ichi,Luo, Fen-Tair
, p. 1560 - 1562 (2007/10/02)
Alkenylmetals of Zn or Al containing α-alkoxy, α-alkylthio, or α-trialkylsilyl substituents react readily with aryl or alkenyl halides in the presence of a Pd catalyst to produce arylated alkenes or conjugated dienes, respectively, the stereospecificity of the reactions for the synthesis of 1, 3, 4, and 5 being > or = 98percent.
