1. Low valent of Vanadium catalyst in organic synthesis

2. I. Oxidation of Alcohols Laxmidhar Rout, Adv. Synth. Catal. 2007, 349, 846 – 848 *clean technological process and no halogenated solvents are involved

3. mechanism

4. II.Pinacol Coupling Reaction 1. Secondary Aliphatic Aldehydes Toshikazu Hirao, J. Org. Chem. 1998, 63, 2812-2813

5. mechanism Toshikazu Hirao, Top Curr Chem. 2007, 279: 53–75

6. 2.intramolecular coupling reaction of 1,5- diketone Toshikazu Hirao, J. Org. Chem. 1998, 63, 2812-2813

7. 3.Aromatic aldehydes （ solvent ： water ） Xu, and Toshikazu Hirao J. Org. Chem., 2005, 70 (21), 8594-8596 No addition of a chlorosilane

8. CAT:[V 2 Cl 3 (THF) 6 ] 2 [Zn 2 Cl 6 ] (V:II) some aliphatic aldehydes + aromatic aldehyde(bearing a chiral auxiliary ) → 1,2- diols diastereoisomeric ratios up to 91:9 and enantiomeric excesses up to 84%. Tetrahedron:Asymmetry, 1990, 1(6), 355-358 4. aliphatic aldehydes with aromatic aldehyde(bearing a chiral auxiliary ）

9. III. Homocoupling Toshikazu Hirao, J. Org. Chem. 1996, 61, 366-367 The yield of 2a depended on the amount of chlorotrimethylsilane 1. Coupling of Aldehydes

10. 2.Coupling of Aldimines Bunpei Hatano, Akiya Ogawa, and Toshikazu Hirao* J. Org. Chem., 1998, 25, 9423.

12. mechanism

13. IV. Related Radical-Like Coupling Toshikazu Hirao, J. Org. Chem. 1998, 63, 2812-2813

14. [V 2 Cl 3 (THF) 6 ] 2,[Zn 2 Cl 6 ],(V:II),freshly prepared from VCl 3 (THF) 3 (V:III)by the reduction with Zn Tsutomu Inokuchi, J. Org. Chem., 1991, 16, 4983-4985

15. mechanism

16. b:*Carried out in CH 2 Cl 2 -THF.

17. Tsutomu Inokuchi, J. Org. Chem., 1991, 16, 4983-4985

18. Cyclization of Olefinic Iodoethers to Tetrahydrofurans Cp 2 TiCl 2 was found to be superior to Cp 2 VCl 2 as a catalyst under these reaction conditions Longhu Zhou, and Toshikazu Hirao J. Org. Chem., 2003, 68 (4), 1633-1635

19. V. stereoselective cyclodimerization Longhu Zhou and Toshikazu Hirao, Tetrahedron Letters, 2000, 41, 8517–8521 Reaction conditions: benzylidene malononitrile (1 mmol), Cp 2 VCl 2 (5 mol%), Zn (2 mmol), Me3SiCl (2 mmol), DMF (5 mL), Ar, rt, 3 h.

20. 3a (24% yield with excellent diastereoselectivity (98:2) 2a (58% yield, 80:20) *3a was converted to 2a on treatment with silica gel overnight *18 h, only 2a was formed,

21. VI. Dehalogenative Coupling *R2 is bigger. *the coordination of the phosphorus raises the reduction capability and selectivity. *the bulky reductant is liable to approach the bromide from the less hindered side Toshikazu Hirao ， J. Org. Chem., 1993, 58 (23), 6529-6530

22. VII. A Novel C−C Single Bond Formation Yasutaka Kataoka,*J. Org. Chem. 1996, 61, 6094-6095 1. V with Grinard reagent *cleavage of the C-O bond at the benzylic position was easy

23. As the amount of allyl bromide increased, the yield of the coupling product 1a decreased gradually while the amount of 3 increased. * clarify the effect of the added O 2

24. Mechanism: 1a, under high dilution conditions. Yasutaka Kataoka,*J. Org. Chem. 1997, 62, 8109-8113

25. The cleavage of the C-O bond at the allylic position also proceeded similarly.

26. Yasutaka Kataoka, J. Org. Chem. 1996, 61, 6094-6095 2. V with ZnR 2 the alkylation of carbonyl compounds the pinacolcoupling reaction the deoxygenative coupling reaction of carbonyl compounds

27. Yasutaka Kataoka, Isamu Makihira, Masaru Utsunomiya, J. Org. Chem., 1997, 62 (24), 8540-8543 a competitive reaction between an aldehyde and a ketone

28. *direct construction of asymmetric quaternary carbons Tetrahedron Letters, 1995, 36, 6495-6498 3. V with Zn and allylic bromide

29. mechanism vanadium(II) species prepared in situ from VCl 3 (thf) 3 and Zn

30. VIII.cross-coupling reaction 1.Alkyl Halides with Aryl Griganard Reagents Shigeo Yasuda,Hideki Yorimitsu* Bull.Chem.Soc. Jpn. 2008, 81, 287-290 Mechanism ：

31. Prove the radical intermediate

32. mechanism

33. IX. Potent Dinuclear Catalysts for Olefin Copolymerization