Sm/HOAc/EtOH System–Mediated Reduction of Baylis–Hillman Acetates
摘要:
Selective formation of (2E)-2-methylalk-2-enoates or 2-methyl alkanoates could be achieved in moderate to good yields under mild conditions via Sm/HOAc/EtOH system-mediated reduction of Baylis-Hillman acetates depending on the amount of samariurn consumed in the reactions.
The α-arylation of sterically hindered silyl ketene acetals (SKAs) with sterically hindered aryl bromides occurs efficiently using Pd[P(t-Bu)3]2 as the optimal catalyst and ZnF2 as a promoter. Less sensitive P(t-Bu)3-based catalysts could be also employed but showed a lower activity. The reaction showed a broad scope with regard to both coupling partners, including heteroaryl bromides and cyclic SKAs
Palladium-Catalyzed β Arylation of Carboxylic Esters
作者:Alice Renaudat、Ludivine Jean-Gérard、Rodolphe Jazzar、Christos E. Kefalidis、Eric Clot、Olivier Baudoin
DOI:10.1002/anie.201003544
日期:——
Alter ego: In the presence of an appropriate palladium(0) catalyst, carboxylicesters underwent β arylation instead of the more common α‐arylation reaction with aryl halides containing an ortho electronegative substituent (see scheme; Cy=cyclohexyl). An asymmetric version of the reaction gave the product with an enantiomeric ratio of up to 77:23.
Selective formation of (2E)-2-methylalk-2-enoates or 2-methyl alkanoates could be achieved in moderate to good yields under mild conditions via Sm/HOAc/EtOH system-mediated reduction of Baylis-Hillman acetates depending on the amount of samariurn consumed in the reactions.