Sezen Bengü, Franz Roberto, Sames Dalibor
Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA.
J Am Chem Soc. 2002 Nov 13;124(45):13372-3. doi: 10.1021/ja027891q.
A new system for catalytic arylation and alkenylation of alkane segments has been developed. The ortho-tert-butylaniline substrates and 2-pivaloylpyridine may be arylated and alkenylated at the tert-butyl group, while no functionalization occurred at more reactive C-H and other bonds. Arylation and alkenylation of these substrates are achieved in the presence of Ph2Si(OH)Me and Ph-CH=CH-Si(OH)Me2, respectively, and the catalytic amount of Pd(OAc)2 and stoichiometric oxidant (Cu(OAc)2, 2 equiv) in DMF. In contrast, the ortho-i-propylaniline substrate underwent cyclopalladation, but no arylation product was obtained. Complex compound 14 was synthesized via tandem arylation-alkenylation of tert-butylaniline 11. We hypothesize that the high selectivity of this system stems from the confluence of directing effect of the Schiff base or pyridine moiety and unique reactivity properties of a phenyl-palladium acetate species (Ph-Pd-OAc.Ln).
已开发出一种用于烷烃片段催化芳基化和烯基化的新体系。邻叔丁基苯胺底物和2-新戊酰基吡啶可在叔丁基处进行芳基化和烯基化，而在反应性更高的C-H键和其他键处未发生官能化。这些底物的芳基化和烯基化分别在Ph2Si(OH)Me和Ph-CH=CH-Si(OH)Me2存在下，以及在DMF中催化量的Pd(OAc)2和化学计量的氧化剂（Cu(OAc)2，2当量）存在下实现。相比之下，邻异丙基苯胺底物发生了环钯化，但未得到芳基化产物。通过叔丁基苯胺11的串联芳基化-烯基化反应合成了配合物14。我们推测该体系的高选择性源于席夫碱或吡啶部分的导向作用与苯基钯乙酸酯物种（Ph-Pd-OAc.Ln）独特的反应性质的共同作用。
