153414-47-2Relevant academic research and scientific papers
Diphenylamido precursors to bisalkoxide molybdenum olefin metathesis catalysts
Sinha, Amritanshu,Schrock, Richard R.,Mueller, Peter,Hoveyda, Amir H.
, p. 4621 - 4626 (2008/10/09)
We have found that Mo(NAr)(CHR′)(NPh2)2 (R′ = t-Bu or CMe2Ph) and Mo(NAr′)(CHCMe 2Ph)-(NPh2)2 (Ar = 2,6-i-Pr2C 6H3; Ar′ = 2,6-Me2C6H 3) can be prepared through addition of 2 equiv of LiNPh2 to Mo(NR″)(CHR′)(OTf)2(dme) species (R″ = Ar or Ar′, dme = 1,2-dimethoxyethane), although yields are low. A high-yield route consists of addition of LiNPh2 to bishexafluro-tert-butoxide species. An X-ray structure of Mo(NAr)(CHCMe2Ph)(NPh 2)2 reveals that the two diphenylamido groups are oriented in a manner that allows an 18-electron count to be achieved. The diphenylamido complexes react readily with t-BuOH and (CF3)2MeCOH, but not readily with the sterically demanding biphenol H2[Biphen] (Biphen2- = 3,3′-di-tert-butyl-5,5′,6,6′- tetramethyl-1,1′-biphenyl-2,2′-diolate). The diphenylamido complexes do react with various 3,3′-disubstituted binaphthols to yield binaphtholate catalysts that can be prepared in situ and employed for a simple asymmetric ring-closing metathesis reaction. In several cases conversions and enantioselectivities were comparable to reactions in which isolated catalysts were employed.
Ligand variation in alkylidene complexes of the type Mo(CHR)(NR')(OR'')2
Oskam, John H.,Fox, Harold H.,Yap, Kimo B.,McConville, David H.,O'Dell, Richard,et al.
, p. 185 - 198 (2007/10/02)
A variety of complexes of the type Mo(NR)2Cl2L2 (R=4-Br-2,6-i-Pr2-C6H2, 4-CN-2,6-i-Pr2-C6H2, 3,5-Me2-C6H3, 2-i-Pr-C6H4, 2-CF3-C6H4, 2-Ph-C6H4, and 1-adamantyl; L=1/2 DME or pyridine) have been synthesized by treating 2 with four equivalents of RNH2 in the presence of Me3SiCl and Et3N.They are readily alkylated by Grignard reagents to give complexes of the type Mo(NR)2(CH2R')2 (R=4-Br-2,6-i-Pr2-C6H2, 4-CN-2,6-i-Pr2-C6H2, 2,6-Me2-C6H3, 3,5-Me2-C6H3, 2-t-Bu-C6H4, 2-i-Pr-C6H4, 2-CF3-C6H4, 2-Ph-C6H4, 1-adamantyl, R'=t-Bu or PhMe2C) from which alkylidene complexes of the type Mo(NR)(CHR')(OTf)2(DME) are formed upon addition of triflic acid.Addition of various alkoxides to the triflate complexes yields four-coordinate complexes of the type Mo(NR)(CHR')(OR'')2 (combinations include R=2,6-i-Pr2-C6H3, 4-Br-2,6-iPr2-C6H2, 4-CN-2,6-i-Pr2-C6H2, 2,6-Me2-C6H3, 3,5-Me2-C6H3, 2-t-Bu-C6H4, 2-i-Pr-C6H4, 2-CF3-C6H4, 2-Ph-C6H4, and 1-adamantyl; OR''=OCMe3, OCEt3, O-1-adamantyl, OCHMe2, OCMe2(CF3), OCMe(CF3)2, OC(CF3)3, and OC(CF3)2CF2CF2CF3).
