Studies Of Synthesis, Structure And Relative Reactions Of Amino And Diketiminato Complexes Containing A Nitrogenous Group On The Carbon Framework

The main research work of this dissertation consists of three parts: Studying some synthesis methods of amido and imino ligands and their relating reactions;Preparation of a series of novel metal complexes;Studying on their chemical structure mainly by NMR and single crystal X-ray. The details is as following.Chapter 1. The history and developments of this thesis woking are reviewed. It is divided into three sections. (1) The application and progresses of amidometal complexes in organic synthesis and catalysis;(2) Synthesis and structures of β-diketiminato metal complexes;(3) Synthesis and coordination mode of amido, amidinato and pyridinato ligands and metal complexes.Chapter 2. Addition reactions of bis(trimethylsilyl) methyl lithium with dimethylcyanamide, 1-piperidinecarbonitrile, and o-, m- and p- cyanopyridine was studied, respectively. A series of symmetrical and unsymmetrical β-diketiminatolithium 2a-2g containing nitrogen substituted group were synthesized and characterized (Scheme 1).Chapter 3. Some symmetrical and unsymmetrical metal (such as Ge, Sn, Ni, Co and Zr) β-diketiminato complexes 3a-3e (Scheme 2) and 3f-3h (Scheme 3) were synthesized and characterized by ¹HNMR, ¹³CNMR, elemental analysis and X-ray diffraction. The proposed reaction mechanisms were discussed.Scheme 3 The synthetic route of compounds 3f-3hChapter 4. Bis(silyl-substituted)methyl- and 1-Azaallyl-lithium, have been found to catalyze α-H-free nitriles directly to yield uniformed and mixed substituted2,4,6-trisubsituted-s-triazines. The generally high yields and relatively mild reaction conditions of this procedure suggest it as an alternative to other aromatic nitrile cyclotrimerization reactions. Of the a-H-free nitriles studied, 4f-4h got significantly reduced yields, the other triazines 4a-4e and 4i-4k got good yields respectively. Silicotropic rearrangements from C to N or N to N and an unusual elimination of LiCHR2 and LiCR2R (R=SiMe3, R'=SiMe2NMe2) were observed.Li[CR'R2] LilCHRz] N^N 4a R1 = Me2N-I -*1T" "^T^ II I 4bRi=1-Piperidy.4CR1 h f g 24dRi=m-Tolyl f N/^ 4h R2 = 1-PiperidylmTolyl f N^4eRi=p-T0lyl jL ^N ^ ^ 41 ^ - m - Pyrtdyl4f Ri=o-Tolyl RHC^NHFrfr J iJ Ll R2 N R2pT0lyl j . ^ ^ ^i=o-Tolyl RHC^NHFr-fr^ J i 4j R2 = pJ L R2 N R2 4k R2 = o-PyridylScheme 4 The synthetic route of s-triazine compounds 4a-4k5dlej *>Scheme 5 The synthetic route of bridged compounds 5a-5eChapter 5. Some bridged via hetero atom (Si, P) chelate complexes containing pyridine ligand 5a-5e (Scheme 5) were prepared from the parent compound 2-methylpyridine. The bulky substituents on 2-amino-6-methylpyridine ligans 5f-5i(Scheme 6) were synthesized and structurally characterized by 'HNMR, 13CNMR, elemental analysis and X-ray difi&action. The proposed mechanism was studied here.Bunl_iH3(T N" NH22BunLiBunLi2SiMe3CIN(SiMe3)2Li51BunUH3