difficulty in prejudgment of the reaction coordinate. To overcome this problem,
automated reaction path search methods, such as the artificial force-induced reaction
(AFIR) method, have been developed. The concept of the AFIR method is that the
reactive parts are pushed together (or pulled apart) by the artificial force to surmount
the activation barrier. The AFIR method does not require the information on the
products as well as the reaction coordinates. The TSs having different conformations
as well as those affording major and minor products can be gathered exhaustively.
The obtained numerous TSs are useful to estimate the product ratio (selectivity),
which is done by the conventional Boltzmann distribution analysis or using an
advanced kinetic method like the rate constant matrix contraction (RCMC) method.
The AFIR method has three algorithms called MC-AFIR, SC-AFIR, and
DS-AFIR. MC-AFIR is powerful to find the TSs for the specific reaction step. In
the case studies of the lanthanide-catalyzed Mukaiyama aldol reactions, the
MC-AFIR was used to gather the TSs of the rate-determining steps exhaustively.
The experimental stereo ratios were reproduced by considering the Boltzmann
distribution of all obtained TSs. A comparison of the two lowest TSs was not enough
to get a deep insight into the origin of the stereoselectivity. We also introduced two
case studies of the SC-AFIR. For hydroformylation of ethylene catalyzed by HCo
(CO) 3 , a reaction path network consisting of both the major channel and the channels
to various byproducts was generated automatically. Furthermore, the systematic
extraction of reaction mechanisms from the complex reaction path network was
demonstrated using the RCMC method. In the application to asymmetric isomerization catalyzed by Rh-BINAP, it was demonstrated that using the ONIOM method
and adopting appropriate options of the SC-AFIR allowed us to generate a reaction
path network for the system consisting of more than 100 atoms. These examples
illustrated the practical applicability of automated reaction path search using the
AFIR method to studies on the mechanisms of organometallic reactions.
References
1. Koga N, Morokuma K (1991) Chem Rev 91:823
2. Niu S, Hall MB (2000) Chem Rev 100:353
3. Ziegler T, Autschbach J (2005) Chem Rev 105:2695
4. Thiel W (2014) Angew Chem Int Ed 53:8605
5. Schlegel HB (2011) WIREs Comput Mol Sci 1:790
6. Jaffe RL, Hayes DM, Morokuma K (1974) J Chem Phys 60:5108
7. Elber R, Karplus M (1987) Chem Phys Lett 139:375
8. Choi C, Elber R (1991) J Chem Phys 94:751
9. Ayala PY, Schlegel HB (1997) J Chem Phys 107:375
10. Henkelman G, Uberuaga BP, Jónsson H (2000) J Chem Phys 113:9901
11. Weinan E, Ren W, Vanden-Eijnden E (2002) Phys Rev B 66:052301
12. Peters B, Heyden A, Bell AT, Chakraborty A (2004) J Chem Phys 120:7877
13. Maeda S, Ohno K (2005) Chem Phys Lett 404:95
14. Behn A, Zimmerman PM, Bell AT, Head-Gordon M (2011) J Chem Phys 135:224108
15. Maeda S, Ohno K (2008) J Am Chem Soc 130:17228
78
M. Hatanaka et al.
automated reaction path search methods, such as the artificial force-induced reaction
(AFIR) method, have been developed. The concept of the AFIR method is that the
reactive parts are pushed together (or pulled apart) by the artificial force to surmount
the activation barrier. The AFIR method does not require the information on the
products as well as the reaction coordinates. The TSs having different conformations
as well as those affording major and minor products can be gathered exhaustively.
The obtained numerous TSs are useful to estimate the product ratio (selectivity),
which is done by the conventional Boltzmann distribution analysis or using an
advanced kinetic method like the rate constant matrix contraction (RCMC) method.
The AFIR method has three algorithms called MC-AFIR, SC-AFIR, and
DS-AFIR. MC-AFIR is powerful to find the TSs for the specific reaction step. In
the case studies of the lanthanide-catalyzed Mukaiyama aldol reactions, the
MC-AFIR was used to gather the TSs of the rate-determining steps exhaustively.
The experimental stereo ratios were reproduced by considering the Boltzmann
distribution of all obtained TSs. A comparison of the two lowest TSs was not enough
to get a deep insight into the origin of the stereoselectivity. We also introduced two
case studies of the SC-AFIR. For hydroformylation of ethylene catalyzed by HCo
(CO) 3 , a reaction path network consisting of both the major channel and the channels
to various byproducts was generated automatically. Furthermore, the systematic
extraction of reaction mechanisms from the complex reaction path network was
demonstrated using the RCMC method. In the application to asymmetric isomerization catalyzed by Rh-BINAP, it was demonstrated that using the ONIOM method
and adopting appropriate options of the SC-AFIR allowed us to generate a reaction
path network for the system consisting of more than 100 atoms. These examples
illustrated the practical applicability of automated reaction path search using the
AFIR method to studies on the mechanisms of organometallic reactions.
References
1. Koga N, Morokuma K (1991) Chem Rev 91:823
2. Niu S, Hall MB (2000) Chem Rev 100:353
3. Ziegler T, Autschbach J (2005) Chem Rev 105:2695
4. Thiel W (2014) Angew Chem Int Ed 53:8605
5. Schlegel HB (2011) WIREs Comput Mol Sci 1:790
6. Jaffe RL, Hayes DM, Morokuma K (1974) J Chem Phys 60:5108
7. Elber R, Karplus M (1987) Chem Phys Lett 139:375
8. Choi C, Elber R (1991) J Chem Phys 94:751
9. Ayala PY, Schlegel HB (1997) J Chem Phys 107:375
10. Henkelman G, Uberuaga BP, Jónsson H (2000) J Chem Phys 113:9901
11. Weinan E, Ren W, Vanden-Eijnden E (2002) Phys Rev B 66:052301
12. Peters B, Heyden A, Bell AT, Chakraborty A (2004) J Chem Phys 120:7877
13. Maeda S, Ohno K (2005) Chem Phys Lett 404:95
14. Behn A, Zimmerman PM, Bell AT, Head-Gordon M (2011) J Chem Phys 135:224108
15. Maeda S, Ohno K (2008) J Am Chem Soc 130:17228
78
M. Hatanaka et al.