Su Weiping, McLeod Dale, Verkade John G
Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
J Org Chem. 2003 Nov 28;68(24):9499-501. doi: 10.1021/jo034815c.
The dimerization of methyl acrylate to the head-to-tail 2-methylene-pentanedioic acid dimethyl ester product was realized in 82 and 85% yield in only 4 h at room temperature in THF in the presence of catalytic amounts of P(RNCH2CH2)3N (R = i-Bu and Bn, respectively). These phosphines are to our knowledge the best nonmetallic catalysts so far reported for this reaction. In contrast, less sterically hindered P(MeNCH2CH2)3N failed to catalyze this dimerization, giving oligomer or polymer instead.
在四氢呋喃（THF）中，在室温下仅4小时，在催化量的P(RNCH₂CH₂)₃N（R分别为异丁基和苄基）存在下，丙烯酸甲酯二聚形成头对尾的2-亚甲基-戊二酸二甲酯产物，产率分别为82%和85%。据我们所知，这些膦是迄今为止报道的该反应最好的非金属催化剂。相比之下，空间位阻较小的P(MeNCH₂CH₂)₃N不能催化这种二聚反应，而是生成低聚物或聚合物。
