ALLYLIC CARBONATES - EFFICIENT ALLYLATING AGENTS OF CARBONUCLEOPHILES IN PALLADIUM CATALYZED-REACTIONS UNDER NEUTRAL CONDITIONS
ALLYLIC CARBONATES - EFFICIENT ALLYLATING AGENTS OF CARBONUCLEOPHILES IN PALLADIUM CATALYZED-REACTIONS UNDER NEUTRAL CONDITIONS
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DOI：
10.1021/jo00209a032
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发表时间：
1985-01-01
影响因子：
3.6
通讯作者：
TAKAHASHI, K
中科院分区：
文献类型：
--
作者：
TSUJI, J;SHIMIZU, I;TAKAHASHI, K
结果1. d-酮酯和丙二酸酯的烯丙基化。首先进行2-甲基-3-氧代戊酸甲酯（11）与各种烯丙基化合物的烯丙基化，以比较使用与PPh 3组合的钯络合物作为催化剂的烯丙基化合物的反应性。如表I所示，碳酸二烯丙酯（12）的反应在室温下不加碱在10分钟内迅速进行，以几乎定量的产率得到烯丙基化产物13。11与碳酸酯12的烯丙基化反应甚至在-78 ℃下进行.二异丙基氨基甲酸烯丙酯（14）在脱羧后产生酰胺阴离子，具有类似的反应性，并得到良好的结果。另一方面，在室温和中性条件下，与烯丙基苯基醚（16）不发生反应，但在65 ℃下反应7.5小时，产物13以62%的产率得到。乙酸烯丙酯（15）和磷酸烯丙酯（17）在无碱条件下反应性较差，但加入化学计量的NaH后反应性良好。与烯丙醇（18）和二烯丙基醚（19）几乎不发生反应。以亚磷酸酯为配体，比较了烯丙基碳酸酯和烯丙基乙酸酯的反应活性。当使用亚磷酸三乙酯代替PPh 3时，乙酸烯丙酯（15）在没有碱的情况下几乎不反应（方案III）。而碳酸二烯丙酯（12）反应平稳。亚磷酸三苯酯，
Results 1. Allylation of d-Keto Esters and Malonates. At first allylation of methyl 2-methyl-3-oxopentanoate (11) with various allylic compounds was carried out in order to compare the reactivity of allylic compounds using palladium complexes combined with PPh3 as the catalyst. As shown in Table I, reaction of diallyl carbonate (12) proceeded rapidly in 10 min without addition of a base at room temperature to give the allylated product 13 in nearly quantitative yield. The allylation of 11 with the carbonate 12 proceeded even at-78 C. Allyl diisopropylcarbamate (14), which generates amide anion after decarboxylation, is similarly reactive and gave a good result. On the other hand, no reaction took place withallyl phenyl ether (16) at room temperature under neutral conditions, but the product 13 was obtained in 62% yield by the reaction at 65 C for 7.5 h. 14 Allyl acetate (15) and allyl diethyl phosphate (17) showed poor reactivity in the absence of a base, but satisfactoryresults were obtained by the ad-dition of a stoichiometric amount of NaH. Almost no reaction took place with allyl alcohol (18) and diallyl ether (19). Reactivities of allylic carbonates and allylic acetates were compared by using phosphites as ligand which are less effective than PPh3. When triethyl phosphite was used instead of PPh3, allyl acetate (15) scarcely reacted without a base (Scheme III). On theother hand, the diallyl car-bonate (12) reacted smoothly. Triphenyl phosphite gave