Re: CCL:TM oxidative addition/reductive elimination to the C-C bond

[smori # - at - # utsc3.chem.s.u-tokyo.ac.jp (Seiji Mori)]

 Dear Dr. Ananikov:
 I have experiences of C-C bond forming process you said as to organocopper
 case .
 In the reductive elimination from Me3Cu(Me2O) and Me3Cu(H2O), Dorigo and
 Schleyer
  (Angew. Chem. Int. Ed. Engl. 1995, 34, 476)
 and Snyder (J. Am. Chem. Soc. 1995, 117, 11025)  show three-centered
 transition state
 using all-electron basis set and ECP, respectively.
 Snyder's ECP results are good agreement with Dorigo's AE results.
 We (Nakamura, Mori, Nakamura, Morokuma, JACS, 1997, 119, 4887 and
 Nakamura, Mori, Morokuma, JACS, 1997, 119, 4900) also have shown that
 in the case of organocopper reaction with acetylene and acrolein.
 In the acetylene addition, the geometry using relavistic ECP using Dolg et
 al. are found to be
 essentially the same as that using AE. (As to second and third-row TM,
 relavistic effects
 are not small. See. Pyykko, Chem. Rev. 1988, 88, 563.)
   In the paper on the conjugate addition to acrolein, we showed TSs in the
 oxidative addition
  and reductive elimination.
 The oxidative addition TS can be viewed as three-centered.
 Reductive elimination TS can be viewed as not only three-centered but also
 four-centered.
 I hope my comment is your help.
 Sincerely yours,
  Seiji Mori
 At 4:14 AM 97.6.24, Ananikov V.P. wrote:
 > Dear All,
 >
 >          I would like to know if anyone have an experience in reaction
 > pathway calculations of Transition Metals insertion(oxidative addition)
 > to the C-C bond and corresponding reverse process(reductive elimination)
 > as well.  There are many examples of TM addition to H-H, C-H, Si-H bonds,
 > but only a few references concerning C-C bond breaking/forming by TM
 > complexes.
 >
 > Does ECP provide sufficient accuracy level for these calculations?
 > How important are electron correlation and relativistic effects on third
 > row elements?
 >
 > In case of insertion to the X-H bond the reactions were found to proceed
 > through three-centered transition state, i.e.:
 >
 >                                  X  - H
 >                                   \  /
 >                                    TM
 >
 > Is it correct to guess the same transition state structure for insertion
 > to the C-C bond?
 >
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 ~  Seiji Mori.(M.Sc.)
 ~
 ~  Graduate student
 ~  Lab. of Physical Organic Chemistry, Department of Chemistry
 ~  The University of Tokyo
 ~  Hongo 7-3-1, Bunkyo-ku, Tokyo 113, JAPAN.
 ~  email:smori # - at - # utsc3.chem.s.u-tokyo.ac.jp
 ~  TELE FAX：　　+81-3-3812-8099
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