Facile pinacol coupling of aliphatic ketones by Brook rearrangement in the presence of samarium species
作者:Xincan Wang、Guanqun Xie、Yanfei Zhao、Ke Zheng、Yanxiong Fang、Xiaoxia Wang
DOI:10.1016/j.tetlet.2021.153069
日期:2021.5
Herein we report a practical pinacol coupling reaction, in which ketones (aldehydes) react smoothly with Sm and TMSBr to afford the diol products with Sm(II) or (III) siliyl species generated in situ. This reported method affords poor yields for aromatic ketone substrates and good yields for aliphaticketones. Therefore, it distinguishes from most reductive coupling approaches that are more effective for
Alkylative Reduction of Titanium(IV) Isopropoxide with EtMgBr: Convenient Method for the Generation of Subvalent Titanium Alkoxide Reagents and their Reactivity in Pinacol Coupling Reactions
作者:Oleg G. Kulinkovich、Evgenii A. Matiushenkov、Nikolai A. Sokolov
DOI:10.1055/s-2003-43370
日期:——
products from the reaction of Ti(IV) isopropoxide with ethylmagnesium bromide in diethyl ether evidences the formation of subvalent titaniumisopropoxide species in various oxidation states depending on relative amounts of the reactants. Reaction of titanium(IV) isopropoxide with one equivalent of the Grignard reagent gives presumably titanium(III) isopropoxide. The latter is generated as a result
Diastereoselective Ce(III)-Catalyzed Pinacol Couplings of Aldehydes
作者:Ulrich Groth、Mario Jeske
DOI:10.1055/s-2001-9692
日期:——
Aliphatic and aromatic aldehydes were converted into the corresponding pinacoles by using different cerium catalysts. Ce(OtBu)3 proved to be superior over other cerium(III) catalysts. Especially the highly diastereoselective pinacol coupling of sterically non demanding aldehydes such as hexanal is remarkable.