Skip to main content

Scandium terminal imido complex induced intramolecular C-N bond cleavage and transformation


The scandium terminal imido complex supported by a monoanionic tetradentate NNNN ligand, [LSc=N(DIPP)] (L = [MeC(N(DIPP))CHC(Me)(NCH2CH2N(Me)CH2CH2NMe2], DIPP = 2,6-(iPr)2C6H3) (1), undergoes a C-N bond cleavage at elevated temperature to give a mononuclear scandium anilido intermediate 2a, which subsequently aggregates into a binuclear scandium anilido complex 2. The mononuclear intermediate 2a reacts with alkyne or imine to provide two scandium anilido complexes 3 and 4, which contain a dianionic tetradentate NNNC ligand or a dianionic tetradentate NNNN ligand. DFT calculations on the reaction mechanism of C-N bond cleavage in 1 were also performed.

This is a preview of subscription content, access via your institution.


  1. 1

    Wigley DE. Organoimido complexes of the transition-metals. Pro Inorg Chem, 1994, 42: 239–482

    CAS  Article  Google Scholar 

  2. 2

    Schrock RR. Living ring-opening metathesis polymerization catalyzed by well-characterized transition-metal alkylidene complexes. Acc Chem Res, 1990, 23: 158–165

    CAS  Article  Google Scholar 

  3. 3

    Duncan AP, Bergman RG. Selective transformations of organic compounds by imidozirconocene complexes. Chem Rec, 2002, 2: 431–445

    CAS  Article  Google Scholar 

  4. 4

    Hazari N, Mountford P. Reactions and applications of titanium imido complexes. Acc Chem Res, 2005, 38: 839–849

    CAS  Article  Google Scholar 

  5. 5

    Mindiola DJ. Oxidatively induced abstraction reactions. A synthetic approach to low-coordinate and reactive early transition metal complexes containing metal-ligand multiple bonds. Acc Chem Res, 2006, 39: 813–821

    CAS  Article  Google Scholar 

  6. 6

    Giesbrecht GR, Gordon JC. Lanthanide alkylidene and imido complexes. Dalton Trans, 2004: 2387–2393

    Google Scholar 

  7. 7

    Liu ZX, Chen YF. One frontier of the rare-earth organometallic chemistry: the chemistry of rare-earth-metal alkylidene, imido and phosphinidene complexes. Sci Sin Chim, 2011, 41: 304–313

    CAS  Article  Google Scholar 

  8. 8

    Summerscales OT, Gordon JC. Complexes containing multiple bonding interactions between lanthanoid elements and main-group fragments. RSC Adv, 2013, 3: 6682–6692

    CAS  Article  Google Scholar 

  9. 9

    Trifonov AA, Bochkarev MN, Schumann H, Loebel J. Reduction of azobenzene by naphthaleneytterbium: a tetranuclear ytterbium(III) complex combining 1,2-diphenyIhydrazido(2-) and phenylimido ligands. Angew Chem Int Ed, 1991, 30: 1149–1151

    Article  Google Scholar 

  10. 10

    Xie ZW, Wang SW, Yang QC, Mak TCW. Synthesis and structure of the first tetranuclear organolanthanide cluster containing a μ4-imido group. Organometallics, 1999, 18: 1578–1579

    CAS  Article  Google Scholar 

  11. 11

    Wang SW, Yang QC, Mak TCW, Xie ZW. Synthesis and structural characterization of novel organolanthanide clusters containing amido and imido groups. Organometallics, 1999, 18: 5511–5517

    CAS  Article  Google Scholar 

  12. 12

    Chan HS, Li HW, Xie ZW. Synthesis and structural characterization of imido-lanthanide complexes with a metal-nitrogen multiple bond. Chem Commun, 2002: 652–653

    Google Scholar 

  13. 13

    Gordon JC, Giesbrecht GR, Clark DL, Hay PJ, Keogh DW, Poli R, Scott BL, Watkin JG. The first example of a µ2-imido functionality bound to a lanthanide metal center: X-ray crystal structure and DFT study of [(µ-ArN)Sm(µ-NHAr)(µ-Me)AlMe2]2 (Ar = 2,6-iPr2C6H3). Organometallics, 2002, 21: 4726–4734

    CAS  Article  Google Scholar 

  14. 14

    Beetstra DJ, Meetsma A, Hessen B, Teuben JH. (Cyclopentadienylamine) scandium(2,3-dimethyl-1,3-butadiene): a 1,3-diene complex of scandium with Sc(I)- and Sc(III)-like reactivity. Organometallics, 2003, 22: 4372–4374

    CAS  Article  Google Scholar 

  15. 15

    Avent AG, Hitchcock PB, Khvostov AV, Lappert MF, Protchenko AV. Reactions of Li- and Yb-coordinated N,N]t’-bis(trimethylsilyl)-β-diketiminates: one- and two-electron reductions, deprotonation, and C-N bond cleavage. Dalton Trans, 2004: 2272–2280

    Google Scholar 

  16. 16

    Cui DM, Nishiura M, Hou ZM. Lanthanide-imido complexes and their reactions with benzonitrile. Angew Chem Int Ed, 2005, 44: 959–962

    CAS  Article  Google Scholar 

  17. 17

    Berthet JC, Thuery P, Ephritikhine M. Polyimido clusters of neodymium and uranium, including a cluster with an M63-N)8 core. Eur J Inorg Chem, 2008: 5455–5459

    Google Scholar 

  18. 18

    Pan CL, Chen W, Song SY, Zhang HJ, Li XW. Stabilization of imidosamarium( III) cubane by amidinates. Inorg Chem, 2009, 48: 6344–6346

    CAS  Article  Google Scholar 

  19. 19

    Pan CL, Chen W, Song JF. Lanthanide(II)-alkali sandwich complexes with cation-arene p interactions: synthesis, structure, and solvent-mediated redox transformations. Organometallics, 2011, 30: 2252–2260

    CAS  Article  Google Scholar 

  20. 20

    Schädle D, Schädle C, Törnroos KW, Anwander, R. Organoaluminum-assisted formation of rare-earth metal imide complexes. Organometallics, 2012, 31: 5101–5107

    Article  Google Scholar 

  21. 21

    Hong JQ, Zhang LX, Wang K, Weng LH, Zhou XG. Methylidene rare-earth metal complex mediated transformations of C=N, N=N and N-H bonds: new routes to imido rare-earth metal clusters. Chem Eur J, 2013, 19: 7865–7873

    CAS  Article  Google Scholar 

  22. 22

    Hong JQ, Zhang LX, Wang K, Chen ZX, Wu LM, Zhou XG. Synthesis, structural characterization, and reactivity of mono(amidinate) rare-earth-metal bis(aminobenzyl) complexes. Organometallics, 2013, 32: 7312–7322

    CAS  Article  Google Scholar 

  23. 23a)

    Tamm and co-workers reported a type of interesting imidazolin-2-iminato complexes of rare-earth-metals. The structural data of the complexes show short metal-nitrogen bonds. See the following and references 24–26

  24. 23b)

    Panda TK, Randoll S, Hrib CG, Jones PG, Bannenberg T, Tamm M. Syntheses and structures of mononuclear lutetium imido complexes with very short Lu-N bonds. Chem Commun, 2007: 5007–5009

    Google Scholar 

  25. 24

    Panda TK, Trambitas AG, Bannenberg T, Hrib CG, Randoll S, Jones PG, Tamm M. Imidazolin-2-iminato complexes of rare earth metals with very short metal-nitrogen bonds: experimental and theoretical studies. Inorg Chem, 2009, 48: 5462–5472

    CAS  Article  Google Scholar 

  26. 25

    Trambitas AG, Panda TK, Jenter J, Roesky PW, Daniliuc C, Hrib CG, Jones PG, Tamm M. Rare-earth metal alkyl, amido, and cyclopentadienyl complexes supported by imidazolin-2-iminato ligands: synthesis, structural characterization, and catalytic application. Inorg Chem, 2010, 49: 2435–2446

    CAS  Article  Google Scholar 

  27. 26

    Trambitas AG, Yang JY, Melcher D, Daniliuc CG, Jones PG, Xie ZW, Tamm M. Synthesis and structure of rare-earth-metal dicarbollide complexes with an imidazolin-2-iminato ligand featuring very short metal-nitrogen bonds. Organometallics, 2011, 30: 1122–1129

    CAS  Article  Google Scholar 

  28. 27

    Scott J, Basuli F, Fout AR, Huffman JC, Mindiola DJ. Evidence for the existence of a terminal imido scandium compound: intermolecular C-H activation and complexation reactions with the transient Sc=NAr species. Angew Chem Int Ed, 2008, 47: 8502–8505

    CAS  Article  Google Scholar 

  29. 28

    Wicker BF, Scott J, Fout AR, Pink M, Mindiola DJ. Atom-economical route to substituted pyridines via a scandium imide. Organometallics, 2011, 30: 2453–2456

    CAS  Article  Google Scholar 

  30. 29

    Wicker BF, Fan HJ, Hickey AK, Crestani MG, Scott J, Pink M, Mindiola DJ. Evidence for the existence of terminal scandium imidos: mechanistic studies involving imido-scandium bond formation and C-H activation reactions. J Am Chem Soc, 2012, 134: 20081–20096

    CAS  Article  Google Scholar 

  31. 30

    Lu EL, Li YX, Chen YF. A scandium terminal imido complex: synthesis, structure and DFT studies. Chem Commun, 2010, 46: 4469–4471

    CAS  Article  Google Scholar 

  32. 31

    Lu EL, Chu JX, Borzov MV, Chen YF, Li GY. Scandium terminal imido complex induced C-H bond selenation and formation of an Sc-Se bond. Chem Commun, 2011, 47: 743–745

    CAS  Article  Google Scholar 

  33. 32

    Jian ZB, Rong WF, Mou ZH, Pan YP, Xie HY, Cui DM. Intramolecular C-H bond activation induced by a scandium terminal imido complex. Chem Commun, 2012, 48: 7516–7518

    CAS  Article  Google Scholar 

  34. 33

    Rong WF, Cheng JH, Mou ZH, Xie HY, Cui DM. Facile preparation of a scandium terminal imido complex supported by a phosphazene ligand. Organometallics, 2013, 32: 5523–5529

    CAS  Article  Google Scholar 

  35. 34

    Chu T, Piers WE, Dutton JL, Parvez M. Synthesis and reactivity of a terminal scandium imido complex. Organometallics, 2013, 32: 1159–1165

    CAS  Article  Google Scholar 

  36. 35

    Lu EL, Zhou QH, Li YX, Chu JX, Chen YF, Leng XB, Sun J. Reactivity of scandium terminal imido complexes towards metal halides. Chem Commun, 2012, 48: 3403–3405

    CAS  Article  Google Scholar 

  37. 36

    Chu JX, Lu EL, Liu ZX, Chen YF, Leng XB, Song HB. Reactivity of a scandium terminal imido complex towards unsaturated substrates. Angew Chem Int Ed, 2011, 50: 7677–7680

    CAS  Article  Google Scholar 

  38. 37

    Chu JX, Kefalidis CE, Maron L, Leng XB, Chen YF. Chameleon behavior of a newly synthesized scandium nitrilimine derivative. J Am Chem Soc, 2013, 135: 8165–8168

    CAS  Article  Google Scholar 

  39. 38

    Chu JX, Lu EL, Chen YF, Leng XB. Reversible addition of the Si-H bond of phenylsilane to the Sc=N bond of a scandium terminal imido complex. Organometallics, 2013, 32: 1137–1140

    CAS  Article  Google Scholar 

  40. 39

    This phenomenon was briefly mentioned in Ref. [31].

  41. 40

    Mungwe N, Swarts AJ, Mapolie SF, Westman G. Cationic palladacycles as catalyst precursors for phenyl acetylene polymerization. J Organomet Chem, 2011, 696: 3527–3535

    CAS  Article  Google Scholar 

  42. 41

    Ge SZ, Meetsma A, Hessen B. Monoanionic fac3 ligands derived from 6-amino-1,4-diazepine: ligand dependence of stability and catalytic activity of their scandium alkyl derivatives. Organometallics, 2007, 26: 5278–5284

    CAS  Article  Google Scholar 

  43. 42

    Tobisch S. Mechanistic investigation of organolanthanide-mediated hydroamination of aminoallenes: a comprehensive computational assessment of various routes for allene activation. Dalton Trans, 2011, 40: 249–261

    CAS  Article  Google Scholar 

  44. 43

    Tobisch S. Mechanistic exploration of intramolecular aminodiene hydroamination/cyclisation mediated by constrained geometry organoactinide complexes: a DFT study. Chem Eur J, 2010, 16: 3441–3458

    CAS  Article  Google Scholar 

  45. 44

    Motta A, Fragalà IL, Marks TJ. Organolanthanide-catalyzed hydroamination/cyclization reactions of aminoalkynes. Computational investigation of mechanism, lanthanide identity, and substituent effects for a very exothermic C-N bond-forming process. Organometallics, 2006, 25: 5533–5539

    CAS  Article  Google Scholar 

  46. 45

    Motta A, Fragalà IL, Motta A, Lanza G, Fragalà IL, Marks TJ. Energetics and mechanism of organolanthanide-mediated aminoalkene hydroamination/cyclization. A density functional theory analysis. Organometallics, 2004, 23: 4097–4104

    CAS  Article  Google Scholar 

  47. 46

    Gagné MR, Stern CL, Marks TJ. Organolanthanide-catalyzed hydroamination. A kinetic, mechanistic, and diastereoselectivity study of the cyclization of N-unprotected amino olefins. J Am Chem Soc, 1992, 114: 275–294

    Article  Google Scholar 

Download references

Author information



Corresponding authors

Correspondence to YuXue Li or YaoFeng Chen.

Additional information

Dedicated to Professor Qian Changtao on the occasion of his 80th birthday.

LI YuXue obtained his B.Sc. from Hebei Normal University in 1997, and his Ph.D. from Beijing Normal University in 2002. From 2002 to 2004, he worked as a postdoctoral fellow at Peking University and later as a research associate in Hong Kong University of Science and Technology. He joined Shanghai Institute of Organic Chemistry (SIOC) as an associate research professor in 2004, and became a research professor in 2011. His research interest is theoretical study on reaction mechanisms.

CHEN YaoFeng received his B.Sc. degree from Hangzhou Normal Colleague in 1993, M.Sc. from Hangzhou University in 1996 under the supervision of Prof. Yuqiu Gong, and Ph.D. from Zhejiang University in 1999 under the supervision of Prof. Zhiquan Shen. He did postdoctoral research in Shanghai Institute of Organic Chemistry (Prof. Changtao Qian’s group, 1999–2002), University of Montreal (Prof. Zargarian Davit’s group, 2002–2003), and University of California, Santa Barbara (Prof. Guillermo C. Bazan’s group, 2003–2005). He joined Shanghai Institute of Organic Chemistry as a research professor in 2006. His research interest is synthesis and reactivity of transition-metal complexes, especially the organometallic complexes of rare-earth metal.

Electronic supplementary material

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Chu, J., Zhou, Q., Li, Y. et al. Scandium terminal imido complex induced intramolecular C-N bond cleavage and transformation. Sci. China Chem. 57, 1098–1105 (2014).

Download citation


  • C-N bond cleavage
  • DFT calculation
  • imido complex
  • scandium