Organotin compounds [Tp*SnCl3-nBun] (2: n = 1; 3: n = 2) having a Tp* ligand (Tp* = tris(3,5-dimethylpyrazol-1-yl)hydroborate) are useful reagents for introducing a Tp* ligand on Group 4 and 5 metals and chromium. The test reactions of these organotin compounds along with [Tp*SnCl3] (1) with ZrCl4, affording a known complex [Tp*ZrCl3] (4), were examined. The reaction rates were in the order 3 > 2  1. This tendency was understood by the average Sn-N(Tp* ligand) bond distance being longer in the order 3 > 2 > 1 as revealed by the crystallographic studies and the orbital interactions between the Tp* ligand and the SnCl3-nBun fragments estimated by the ab initio calculations for 1—3. On the basis of the above findings, we applied the compound 3 to prepare Tp* complexes of Group 4—6 metals. Reactions of TiCl4 with an equimolar amount of 3 afforded [Tp*TiCl3] (7) in good yields after a simple rinse to remove the resulting tin compound, SnBu2Cl2. [Tp*HfCl3] (8) was prepared in moderate yield by reaction of [HfCl4(THF)2] with 3 under severe conditions. Similarly, the reactions of 3 with a stoichiometric amount of [NbCl4(THF)2] or [NbCl5(OEt)2] and TaCl5 in toluene gave [Tp*NbCl3] (9) and [Tp*TaCl3][TaCl6] (10), respectively. We also applied our synthetic method to prepare Tp* complexes of vanadium, [Tp*VCl2(THF)] (11), [Tp*VCl2(DNAP)] (12) (DMAP = 4-dimethylaminopyridine), and [Tp*VCl2(=NC6H3Me2-2,6)] (13) and those of chromium, [Tp*CrCl2(L)] (14: L = THF; 15: L = H2O; 16: L = DMAP). Some of these Tp* complexes, 4, 8, 12, 13, 15, and 16 were crystallographically characterized to have discrete octahedral geometry containing the facial coordination of the Tp* ligand.

Ozonolyses of 3-methyl- and 3-isopropyl-1-methylindenes (1a,b) in ether gave mainly the corresponding oligomers 3a,b, while in the case of 3-phenyl- and 3-tert-butyl-1-methylindenes (1c,d), the corresponding exo−endo mixtures of ozonides 2c,d were obtained in good yield, the exo isomer being the major one. The ozonolyses of two stereoisomeric keto vinyl ethers, (E)-16 and (Z)-16, demonstrated that the stereochemistry of the derived carbonyl oxide 5c exerts a remarkable influence on the course of the reaction. Particularly interesting is the fact that syn-5c having a proper geometry for the concerted cycloaddition provided ozonide 2c in high yield even in the presence of trifluoroacetophenone. The high degree of similarity in the nature and distribution of the products from the ozonolyses of keto olefin (E)-16 and 1-methyl-3-phenylindene (1c) would be consistent with their respective reactions proceeding predominantly through a common carbonyl oxide intermediate syn-5c.

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