Titanium-Mediated Synthesis of 1,4-Diketones from Grignard Reagents and Acyl Cyanohydrins
作者:Paul Setzer、Alice Beauseigneur、Morwenna S. M. Pearson-Long、Philippe Bertus
DOI:10.1002/anie.201003923
日期:2010.11.8
Double duty: In the presence of titanium isopropoxide, Grignard reagents were found to react with acyl cyanohydrins to give substituted 5‐hydroxy‐1,4‐diketones (see scheme). This new reaction involves a formal addition of a 1,2‐dianionequivalent to both the ester and nitrile moieties.
Titanium-Mediated Addition of Grignard Reagents to Acyl Cyanohydrins: Aminocyclopropane versus 1,4-Diketone Formation
作者:Paul Setzer、Gwénaël Forcher、Fabien Boeda、Morwenna S. M. Pearson-Long、Philippe Bertus
DOI:10.1002/ejoc.201301251
日期:2014.1
The 1,2-dianion reactivity of the reagent generated from EtMgBr and titanium isopropoxide was illustrated when N-acyl cyanohydrins were used as substrates (>20 examples), giving both aminocyclopropane derivatives and 1,4-dicarbonyl compounds. When the reaction was performed in diethyl ether, 5-hydroxy-1,4-diketones were the main product. Under specific conditions (use of tetrahydrofuran and a bulky