New Methods for the Syntheses of α,β-Unsaturated Ketones, Aldehydes, and Nitriles by the Palladium-Catalyzed Reactions of Allyl β-Oxo Esters, Allyl 1-Alkenyl Carbonates, and Allyl α-Cyano Esters
作者:Ichiro Minami、Mohammad Nisar、Masami Yuhara、Isao Shimizu、Jiro Tsuji
DOI:10.1055/s-1987-28145
日期:——
Allyl β-oxo esters, allyl 1-alkenyl carbonates, and allyl α-cyano esters are converted into α,β-unsaturated ketones, aldehydes, and nitriles by palladium-catalyzed intramolecular decarboxylation-dehydrogenation. Palladium-phosphine complexes such as Pd(OAc)2-PPh3, Pd(OAc)2-dppe, or Pd2(dba)3 - CHCl3-PPh3 are effective catalysts. Yields depend on solvents and on the mole ratio of palladium to phosphine. The optimum Pd/P ratio for each substrate was determined Use of nitriles as solvents is essential for the dehydrogenation.
烯丙基β-氧代酯、烯丙基1-烯基碳酸酯和烯丙基α-氰基酯通过钯催化的分子内脱羧脱氢反应转化为α,β-不饱和酮、醛和腈。钯-膦配合物如Pd(OAc)2-PPh3、Pd(OAc)2-dppe或Pd2(dba)3-CHCl3-PPh3是有效的催化剂。产率取决于溶剂和钯与膦的摩尔比。每个底物的最佳Pd/P比被确定。使用腈作为溶剂对脱氢是至关重要的。