Ligand variation in alkylidene complexes of the type Mo(CHR)(NR')(OR'')2

Article abstract of DOI:10.1016/0022-328X(93)86071-O

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).