{[Bis(dimethylamino) boryl]methyl} dimethylphosphane as ligand in transition metal complexes

Abstract

The new α,ω[phosphanyl(organyl)]borane Me 2PCH 2B(NMe 2) 2 ( 8) was obtained in good yield by the reaction of ClB(NMe 2) 2 with LiCH 2PMe 2. Compound 8 forms the transition metal complexes [(CO) 5Cr{Me 2PCH 2(NMe 2) 2}] ( 9), [(MeC 5H 4)Mn(CO) 2{Me 2PCH 2B(NMe 2) 2}] ( 10), and [(CO) 4Fe{Me 2PCH 2B(NMc 2) 2}] ( 11). which were isolated as highly volatile liquids in high yields. Complex 11 easily underwent exchange reactions of the Me 2N substituents which led to derivatives with threefold coordinated boron such as [(CO) 4Fe{Me 2PCH 2B(OMe) 2}] ( 13), and [(CO) 4Fe{Me 2PCH 2B(NMe 2)Cl}] ( 14), or to a compound with tetrafold coordinated boron, [(CO) 4Fe{Me 2PCH 2BCl 2(NHMe 2)}] ( 15). Li[(CO) 4Fe(Me 2PCH 2BH 3)] ( 16), cis,trans-[{(CO) 4Fe(Me 2PCH 2BH 2)} 2] ( 17), and [(CO) 4Fe{Me 2PCH 2BH 2(2,4,6-Me 3C 5H 2N)}] ( 18) were obtained from 13 by corresponding substitution of the MeO groups. The addition of HSiPh 3 to the iron center was achieved by photolysis of 13, giving [(CO) 3FeH(SiPh 3){Me 2PCH 2B(OMe) 2}] ( 19). [(CO) 5Cr{Me 2PCH 2B(OMe) 2}] ( 12), the chromium analogue of 13, was obtained from the reaction of [(CO) 5Cr{Me 2PCH 2B(NMe 2) 2}] ( 9) with MeOH. The structure of compound 19 was determined by single crystal X-ray diffraction.