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Metal-organic cooperative catalysis in C-H and C-C bond activation and its concurrent recovery.
Acc Chem Res. 2008 Feb; 41(2):222-34.AC

Abstract

The development of an efficient catalytic activation (cleavage) system for C-H and C-C bonds is an important challenge in organic synthesis, because these bonds comprise a variety of organic molecules such as natural products, petroleum oils, and polymers on the earth. Among many elegant approaches utilizing transition metals to activate C-H and C-C bonds facilely, chelation-assisted protocols based on the coordinating ability of an organic moiety have attracted great attention, though they have often suffered from the need for an intact coordinating group in a substrate. In this Account, we describe our entire efforts to activate C-H or C-C bonds adjacent to carbonyl groups by employing a new concept of metal-organic cooperative catalysis (MOCC), which enables the temporal installation of a 2-aminopyridyl group into common aldehydes or ketones in a catalytic way. Consequently, a series of new catalytic reactions such as alcohol hydroacylation, oxo-ester synthesis, C-C triple bond cleavage, hydrative dimerization of alkynes, and skeletal rearrangements of cyclic ketones was realized through MOCC. In particular, in the quest for an optimized MOCC system composed of a Wilkinson's catalyst (Ph 3P) 3RhCl and an organic catalyst (2-amino-3-picoline), surprising efficiency enhancements could be achieved when benzoic acid and aniline were introduced as promoters for the aldimine formation process. Furthermore, a notable accomplishment of C-C bond activation has been made using 2-amino-3-picoline as a temporary chelating auxiliary in the reactions of unstrained ketones with various terminal olefins and Wilkinson's catalyst. In the case of seven-membered cyclic ketones, an interesting ring contraction to five- or six-membered ones takes place through skeletal rearrangements initiated by the C-C bond activation of MOCC. On the other hand, the fundamental advances of these catalytic systems into recyclable processes could be achieved by immobilizing both metal and organic components using a hydrogen-bonded self-assembled system as a catalyst support. This catalyst-recovery system provides a homogeneous phase at high temperature during the reaction and a heterogeneous phase at room temperature after the reaction. The product could be separated conveniently from the self-assembly support system by decanting the upper layer. The immobilized catalysts of both 2-aminopyridine and rhodium metal species sustained high catalytic activity for up to the eight catalytic reactions. In conclusion, the successful incorporation of an organocatalytic cycle into a transition metal catalyzed reaction led us to find MOCC for C-H and C-C bond activation. In addition, the hydrogen-bonded self-assembled support has been developed for an efficient and effective recovery system of homogeneous catalysts and could be successful in immobilizing both metal and organic catalysts.

Authors+Show Affiliations

Department of Chemistry and Center for Bioactive Molecular Hybrid, Yonsei University, Seoul 120-749.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18247521

Citation

Park, Young Jun, et al. "Metal-organic Cooperative Catalysis in C-H and C-C Bond Activation and Its Concurrent Recovery." Accounts of Chemical Research, vol. 41, no. 2, 2008, pp. 222-34.
Park YJ, Park JW, Jun CH. Metal-organic cooperative catalysis in C-H and C-C bond activation and its concurrent recovery. Acc Chem Res. 2008;41(2):222-34.
Park, Y. J., Park, J. W., & Jun, C. H. (2008). Metal-organic cooperative catalysis in C-H and C-C bond activation and its concurrent recovery. Accounts of Chemical Research, 41(2), 222-34. https://doi.org/10.1021/ar700133y
Park YJ, Park JW, Jun CH. Metal-organic Cooperative Catalysis in C-H and C-C Bond Activation and Its Concurrent Recovery. Acc Chem Res. 2008;41(2):222-34. PubMed PMID: 18247521.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Metal-organic cooperative catalysis in C-H and C-C bond activation and its concurrent recovery. AU - Park,Young Jun, AU - Park,Jung-Woo, AU - Jun,Chul-Ho, Y1 - 2008/02/02/ PY - 2008/2/6/pubmed PY - 2008/4/9/medline PY - 2008/2/6/entrez SP - 222 EP - 34 JF - Accounts of chemical research JO - Acc Chem Res VL - 41 IS - 2 N2 - The development of an efficient catalytic activation (cleavage) system for C-H and C-C bonds is an important challenge in organic synthesis, because these bonds comprise a variety of organic molecules such as natural products, petroleum oils, and polymers on the earth. Among many elegant approaches utilizing transition metals to activate C-H and C-C bonds facilely, chelation-assisted protocols based on the coordinating ability of an organic moiety have attracted great attention, though they have often suffered from the need for an intact coordinating group in a substrate. In this Account, we describe our entire efforts to activate C-H or C-C bonds adjacent to carbonyl groups by employing a new concept of metal-organic cooperative catalysis (MOCC), which enables the temporal installation of a 2-aminopyridyl group into common aldehydes or ketones in a catalytic way. Consequently, a series of new catalytic reactions such as alcohol hydroacylation, oxo-ester synthesis, C-C triple bond cleavage, hydrative dimerization of alkynes, and skeletal rearrangements of cyclic ketones was realized through MOCC. In particular, in the quest for an optimized MOCC system composed of a Wilkinson's catalyst (Ph 3P) 3RhCl and an organic catalyst (2-amino-3-picoline), surprising efficiency enhancements could be achieved when benzoic acid and aniline were introduced as promoters for the aldimine formation process. Furthermore, a notable accomplishment of C-C bond activation has been made using 2-amino-3-picoline as a temporary chelating auxiliary in the reactions of unstrained ketones with various terminal olefins and Wilkinson's catalyst. In the case of seven-membered cyclic ketones, an interesting ring contraction to five- or six-membered ones takes place through skeletal rearrangements initiated by the C-C bond activation of MOCC. On the other hand, the fundamental advances of these catalytic systems into recyclable processes could be achieved by immobilizing both metal and organic components using a hydrogen-bonded self-assembled system as a catalyst support. This catalyst-recovery system provides a homogeneous phase at high temperature during the reaction and a heterogeneous phase at room temperature after the reaction. The product could be separated conveniently from the self-assembly support system by decanting the upper layer. The immobilized catalysts of both 2-aminopyridine and rhodium metal species sustained high catalytic activity for up to the eight catalytic reactions. In conclusion, the successful incorporation of an organocatalytic cycle into a transition metal catalyzed reaction led us to find MOCC for C-H and C-C bond activation. In addition, the hydrogen-bonded self-assembled support has been developed for an efficient and effective recovery system of homogeneous catalysts and could be successful in immobilizing both metal and organic catalysts. SN - 0001-4842 UR - https://www.unboundmedicine.com/medline/citation/18247521/Metal_organic_cooperative_catalysis_in_C_H_and_C_C_bond_activation_and_its_concurrent_recovery_ L2 - https://doi.org/10.1021/ar700133y DB - PRIME DP - Unbound Medicine ER -