Research On Olefin Metathesis Reaction Catalyzed By Phosphinoamine Carbene Complexes

The olefin metathesis mediated by metal-carbene complexes is a rearrangement reaction between a carbon-carbon double bond or a triple bond,which has been widely used in petroleum,pharmaceutical,agricultural,pharmaceutical,polymer and material chemistry fields because of its mild reaction conditions and high yield as well as the tolerance of functional groups.With the development of Grupps ruthenium-carbine catalyst,a large number of novel ruthenium-carbene compounds were preapared in order to increase catalytic activity and selectiviey in rencent years.Among the possible approachs,the modification of the ancillary ligands of catalyst is an important means for achieving good catalytic behaviers.Phosphinoamine is of unique phosphine ligand and was extensively employed in the synthesis of novel orgamometallics and catalysts,but its application in exploration of metal carbine complexes was rare.In this paper,a series of novel carbine-ruthenium complexes supported by phosphinoamine ligands were synthesized and were investigated its catalytic activity in the field of olefin metathesis reactions,the works are as bellow:(1)Ten phosphinoamide compounds bearing different substitutents and two chiral di(phosphinoamine)ligands were synthesized by the reaction between various primary amines and dialkylphosphine chloride.These compounds were characterized by 1H NMR and 31P NMR;(2)Six carbene-ruthenium complexes bearing phosphinoamine ligands were synthesized by the reaction of various phosphinoamine and G1 carbene-rutheniun catalyst,together with a series of carbine-ruthenium complexes bearing one phosphinoamine stemed from the reaction of G2 carbene-ruthenium catalyst.In addition,chiral di(phosphinoamine)carbine-ruthenium complexes were also prepared according the similar procedures.These novel carbine-ruthenium complexes were characterized by ¹H,³¹P NMR and X-ray single crystal diffraction analysis.(3)The catalytic performance of the novel carbine-ruthenium complexes was evaluated through the ring-closing meththesis reaction(CM)ofN,N-diallyl-p-toluenesulfonamide.The results showed that the property of substitutents on the nitrogen and the phosphine of ligands effects on the reaction rate of CM significantly.To our delight,some of them are more active than the classical second-generation Grubbs catalyst and the third-generation Grubbs catalyst;(4)Under the optimized reaction conditions,various olefin metathesis reactions including ring-closing,cross,and ring-opening metathesis were explored and good results are obtained.