Addressing the Poly- to Oligo-ketone Selectivity in Styrene Carbonylation Catalyzed by Palladium/bpy Complexes. Effect of the 6-Alkyl Substitution
作者:Angela D’Amora、Lidia Fanfoni、Daniela Cozzula、Nicol Guidolin、Ennio Zangrando、Fulvia Felluga、Serafino Gladiali、Fabio Benedetti、Barbara Milani
DOI:10.1021/om100585x
日期:2010.10.25
to act as a terdentate N−N′−C ligand. Complexes of series ii feature one chelate N−N′ ligand, while the other one is coordinated to Pd in a monodentate fashion. In solution a fluxional process that makes equivalent the two N−N′ ligands is present, and the static 1H NMR spectra correspond to an averaged structure where palladium is a stereogenic center. All these complexes behave as catalysts for styrene
两个系列的有机金属Pd配合物,(i)[Pd(CH 3)(CH 3 CN)(N-N')] [PF 6 ]和(ii)[Pd(CH 3)(N-N')2 ] [PF 6 ],具有一定范围的6-烷基取代的2,2'-联吡啶配体,包括新的6-(1-甲氧基乙基)-2,2'-联吡啶,呈外消旋和对映纯形式,和2-(甲氧基甲基)-6-(1 H-1,2,3-三唑-1-基)吡啶已被研究。通过两种立体互补化学酶促方法,以外消旋和相反的同手性对映体形式合成了6-(1-甲氧基乙基)-2,2'-联吡啶。在固态和溶液中,新络合物的表征都为形成独特的异构体提供了证据,该异构体的特征是甲基配体反式取代了吡啶环的Pd-N键。对于具有sec的bpy配体的复合物-丁基取代基会发生伴随甲烷释放的环金属化反应,从而导致被取代的bpy充当末端N-N'-C配体。ii系列的配合物具有一个螯合的N'N'配体,而另一个则以单齿的方式与Pd配位。在溶