The Activity Of Organolanthanides On Organic Small Molecules Containing 1,3-Heteroculumenen Bonds

In recent twenty years, important interests have changed from the synthesis ofnovel organolanthanide complexes to the investigation of reactivities and catalyticproperties of these compounds, because these studies will reveal many neworganolanthanide reactions, which maybe promote the application oforganolanthanides in the organic synthesis and alkene polymerization. As theextension of the activity of organolanthanide complexes on unsaturated organic smallmolecules, the thesis focus on investigating the activity of lanthanocence derivativeson the molecules containing 1,3-heteroculumene bonds, carbodiimide, isocyanate andisothiocyanate, etc. Herein we synthesized forty-three new organolanthanidecomplexes, among the structures of thirty-four compounds were determined throughX-ray single crystal diffraction analysis, and described six kinds of novelorganolanthanide reactions. The thesis is composed of nine chapters. In Chapter I, Preface, the main development of organolanthanide chemistry inrecent twenty years is introduced. In Chapter II, We have demonstrated that organolanthanide alkyl derivativesexhibit high activity toward carbodiimide. Carbodiimide inserts readily into the Ln?Cσ-bond of (C5H5)2LnR (R = nBu, Me) under mild conditions, giving theorganolanthanide amidinates (C5H5)2Ln[R'N∴C(R)∴NR'] (R' = Bu, R = nBu, Ln = tEr(2-1), Gd(2-2), Y(2-3); R' = Pr, R = Me, Ln = Yb(2-4), Er(2-5), Gd(2-6)), which iprovides a new way to prepare new lanthanocence derivatives incorporating amidinateligands [R'N∴C(R)∴NR']. Further investigation results suggest that the carbodiimideinsertion is independent of stoichiometry and excess carbodiimide does not undergoany other reaction. The complex 2-3 can catalyze cyclotrimerization of phenylisocyanate. In Chapter III, The synthesis and structures of new lanthanide complexesincorporating tetra-substituted guanidinate ligand [RN∴C(NiPr2)∴NR] are described.Treatment of (C5H5)2LnNiPr2(THF) with PrN=C=NiPr results in mono-insertion of i IV复旦大学博士学位论文 Abstractcarbodiimide into the Ln?N σ-bond to yield (C5H5)2Ln[iPrN∴C(NiPr2)∴NiPr] (Ln =Yb(3-1), Dy(3-2), Gd(3-3)), indicating that the reaction rate significantly depends onthe nature of solvents. Moreover, CyN=C=NCy can also insert into the Yb-N σ-bondof (C5H5)2YbNiPr2(THF), giving the corresponding ytterbocene guanidinate(C5H5)2Yb[CyN∴C(NiPr2)∴NCy] (3-4). The reaction of (C5H5)YCl2(THF)3 withLiNiPr2 and subsequently with two equiv of PrN=C=NiPr in THF gave two kinds of iguandinates Y[iPrN∴C(NiPr2)∴NiPr]3 (3-5) and (C5H5)2Y[iPrN∴C(NiPr2)∴NiPr](3-6), which may be rationalized by the rearrangement reaction of the di-insertionproduct (C5H5)Y[iPrN∴C(NiPr2)∴NiPr]2. All these reactions provide an efficientmethod for the synthesis of organolanthanide guanidinate complexes. In Chapter IV, Treatment of PrN=C=NiPr with lanthanocene primary amides i[(C5H5)2LnNHR]2 gave the unexpected products (C5H5)2Yb[RN∴C(NHiPr)∴NiPr] (R= Bu, Ln = Yb(4-1), Er(4-2), Dy(4-3), Y(4-4); R =Ph, Ln = Yb(4-5)), indicating that a tnovel isomerization involving 1,3-hydrogen shift takes place along with the insertionof carbodiimide into the Ln?N σ-bond. The novel isomerization reactions provide anefficient method for synthesis of organolanthanide complexes with asymmetricalguanidinate ligands. In Chapter V, Abstraction of cyclopentadienyl from (C5H5)3Yb with one equiv ofcarbazole (HCbz) in THF at room temperature gives (C5H5)2YbCbz(THF) (5-1).Reaction of 5-1 with PrN=C=NiPr results in mono-insertion of PrN=C=NiPr into the i...