4 Conclusion
Iron-catalyzed C–H bond activation followed by C–C bond formation has received
much attention in recent years, motivated by the environmental and economical
merits of iron, as well as the scientific challenge in controlling and understanding
the reactivity of iron species. Robust catalytic systems have been developed for
directed C–H bond functionalization with organometallic reagents or with electrophiles, and in some cases versatility and efficiency rivaling precious metal catalysis
have been achieved. Several examples of directed C(sp
3 )–H activation have also
been reported. Nondirected reactions have mostly relied on electron-transfer processes, especially the reactions of C(sp
3 )–H bonds. While the pace of recent
developments is impressive, it can be said that the potential of iron catalysis for
C–H bond functionalization is far from being fulfilled. The repertoire of reactions is
still limited, as is the variety of substrates available; many of these reactions use
reactive organometallics as a base, and in many cases functional group tolerance or
product selectivity is unsatisfactory. Two of the biggest obstacles in the development of these reactions are the lack of mechanistic understanding and implicitly the
lack of guidelines for controlling the reactivity of iron species. It is the belief of the
authors that in the near future these challenges will be successfully addressed, and
efficient iron catalysts for versatile C–H bond functionalization will be achieved.
References
1. Dyker G (ed) (2005) Handbook of C–H transformations. Wiley-VCH, Weinheim
2. Godula K, Sames D (2006) Science 312:67
3. Gutekunst WR, Baran PS (2011) Chem Soc Rev 40:1976
4. Wencel-Delord J, Glorius F (2013) Nat Chem 5:369
5. Segawa Y, Maekawa T, Itami K (2015) Angew Chem Int Ed 54:66
6. Nakamura E, Sato K (2011) Nat Mater 10:158
7. Plietker B (ed) (2008) Iron catalysis in organic chemistry. Wiley-VCH, Weinheim
8. Bolm C (2009) Nat Chem 1:420
9. Kulkarni A, Daugulis O (2009) Synthesis 4087
10. Sun C-L, Li B-J, Shi Z-J (2011) Chem Rev 111:1293
11. Bauer I, Kn€ olker H-J (2015) Chem Rev 115:3170
12. Yoshikai N (2014) Iron-catalyzed cross-coupling reactions. In: Marek I, Rappoport Z (eds)
The chemistry of organoiron compounds. Wiley, Chichester
13. Ambhaikar NB (2015) Iron-catalyzed C–H activation. In: Li JJ (ed) C–H bond activation in
organic synthesis. CRC, Boca Raton
14. Mihovilovic MD, Schnu ¨rch M (2014) ChemCatChem 6:2194
15. Su B, Cao Z-C, Shi Z-J (2015) Acc Chem Rev 48:886
16. Nakamura E, Yoshikai N (2010) J Org Chem 75:6061
17. Bagga MM, Pauson PL, Preston FJ, Reed RI (1965) Chem Commun 543
18. Baikie PE, Mills OS (1966) Chem Commun 707
19. Bagga MM, Flannigan WT, Knox GR, Pauson PL, Preston FJ, Reed RI (1968) J Chem Soc C
36
20. Alper H, Chan ASK (1971) Chem Commun 1203
16
L. Ilies and E. Nakamura
Iron-catalyzed C–H bond activation followed by C–C bond formation has received
much attention in recent years, motivated by the environmental and economical
merits of iron, as well as the scientific challenge in controlling and understanding
the reactivity of iron species. Robust catalytic systems have been developed for
directed C–H bond functionalization with organometallic reagents or with electrophiles, and in some cases versatility and efficiency rivaling precious metal catalysis
have been achieved. Several examples of directed C(sp
3 )–H activation have also
been reported. Nondirected reactions have mostly relied on electron-transfer processes, especially the reactions of C(sp
3 )–H bonds. While the pace of recent
developments is impressive, it can be said that the potential of iron catalysis for
C–H bond functionalization is far from being fulfilled. The repertoire of reactions is
still limited, as is the variety of substrates available; many of these reactions use
reactive organometallics as a base, and in many cases functional group tolerance or
product selectivity is unsatisfactory. Two of the biggest obstacles in the development of these reactions are the lack of mechanistic understanding and implicitly the
lack of guidelines for controlling the reactivity of iron species. It is the belief of the
authors that in the near future these challenges will be successfully addressed, and
efficient iron catalysts for versatile C–H bond functionalization will be achieved.
References
1. Dyker G (ed) (2005) Handbook of C–H transformations. Wiley-VCH, Weinheim
2. Godula K, Sames D (2006) Science 312:67
3. Gutekunst WR, Baran PS (2011) Chem Soc Rev 40:1976
4. Wencel-Delord J, Glorius F (2013) Nat Chem 5:369
5. Segawa Y, Maekawa T, Itami K (2015) Angew Chem Int Ed 54:66
6. Nakamura E, Sato K (2011) Nat Mater 10:158
7. Plietker B (ed) (2008) Iron catalysis in organic chemistry. Wiley-VCH, Weinheim
8. Bolm C (2009) Nat Chem 1:420
9. Kulkarni A, Daugulis O (2009) Synthesis 4087
10. Sun C-L, Li B-J, Shi Z-J (2011) Chem Rev 111:1293
11. Bauer I, Kn€ olker H-J (2015) Chem Rev 115:3170
12. Yoshikai N (2014) Iron-catalyzed cross-coupling reactions. In: Marek I, Rappoport Z (eds)
The chemistry of organoiron compounds. Wiley, Chichester
13. Ambhaikar NB (2015) Iron-catalyzed C–H activation. In: Li JJ (ed) C–H bond activation in
organic synthesis. CRC, Boca Raton
14. Mihovilovic MD, Schnu ¨rch M (2014) ChemCatChem 6:2194
15. Su B, Cao Z-C, Shi Z-J (2015) Acc Chem Rev 48:886
16. Nakamura E, Yoshikai N (2010) J Org Chem 75:6061
17. Bagga MM, Pauson PL, Preston FJ, Reed RI (1965) Chem Commun 543
18. Baikie PE, Mills OS (1966) Chem Commun 707
19. Bagga MM, Flannigan WT, Knox GR, Pauson PL, Preston FJ, Reed RI (1968) J Chem Soc C
36
20. Alper H, Chan ASK (1971) Chem Commun 1203
16
L. Ilies and E. Nakamura