Molybdenum Imido Alkylidene Complexes Containing Biphen Ligands that Have Silyl Groups Attached through the 6 and 6′ Methyl Group Carbon Atoms was written by Hultzsch, Kai C.;Bonitatebus, Peter J. Jr.;Jernelius, Jesper;Schrock, Richard R.;Hoveyda, Amir H.. And the article was included in Organometallics in 2001.Electric Literature of C24H34O2 This article mentions the following:
Two new biphenolate ligands were prepared starting from 3,3′-di-tert-butyl-5,5′,6,6′-tetramethyl-2,2′-dimethoxy-1,1′-biphenyl via deprotonation of the 6 and 6′ Me group with KO-t-Bu/n-BuLi, reaction with dichlorodimethylsilane or chlorotrimethylsilane, and deprotection with boron tribromide. Molybdenum imido alkylidene complexes were prepared by treating Mo(NAr)(CHCMe2Ph)(OTf)2(DME) with the dipotassium salt of each biphenolate. X-ray crystallog. studies of syn-Mo(NAr)(CHCMe2Ph)[(rac)-Me2SiBiphen] and syn-Mo(NAr)(CHCMe2Ph)[(rac)-TMS2Biphen] revealed a significantly different geometry of the biphenolate ligands compared to previously structurally characterized four-coordinate biphenolate molybdenum imido alkylidene complexes. The enantiopure complexes were shown to catalyze asym. olefin metathesis with an enantioselectivity comparable to that of Mo(NAr)(CHCMe2Ph)[(S)-Biphen]. In the experiment, the researchers used many compounds, for example, (S)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol (cas: 205927-03-3Electric Literature of C24H34O2).
(S)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol (cas: 205927-03-3) belongs to copper catalysts. Transition metal-catalyzed chemical transformation of organic electrophiles and organometallic reagents belong to the most important cross-coupling reaction in organic synthesis. Copper of different valence states can be used to catalyze the coupling reaction, especially the Ullmann coupling reaction. Electric Literature of C24H34O2
Referemce:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”