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Iron Catalyzed Cross-Coupling Reaction: Recent Advances and Primary Mechanism. Wang Chao 2010.11.6. General:. Cheap Enviromentally benign Sustainable Unique reactivity. Genesis:. Kharasch: J. Am. Chem. Soc. 1941 , 63 , 2316. Kochi: J. Am. Chem. Soc. 1971 , 93 , 1487.
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Iron Catalyzed Cross-Coupling Reaction: Recent Advances and Primary Mechanism Wang Chao 2010.11.6
General: Cheap Enviromentally benign Sustainable Unique reactivity
Genesis: Kharasch: J. Am. Chem. Soc.1941, 63, 2316 Kochi: J. Am. Chem. Soc.1971, 93, 1487
Alkenyl electrophiles (-)-cubebene (5)
Aryl electrophiles: 菲尔斯特纳Furstner: Angew. Chem., Int. Ed. 2002, 41, 609
allyl, vinyl, and aryl Grignard reagents uniformly led to poor yields in reactions performed with FeX3 (X =Cl, acac) in THF/NMP
a valuable component of liquid-crystalline materials spermidine alkaloid
Alkyl halides the high barrier to oxidative addition b-hydride elimination Nakamura, Eiichi: J. AM. CHEM. SOC. 2004, 126, 3686-3687
L = TMEDA Angew. Chem. Int. Ed. 2004, 43, 3955 –3957
[FeCl (salen)] Bedford: Chem. Commun.2004, 2822–2823. Cahiez: Angew. Chem. Int. Ed. 2007, 46, 4364 –4366
Iron-Phosphine, -Phosphite, -Arsine, and -Carbene Catalysts Bedford: J. Org. Chem. 2006, 71, 1104-1110
Mechanism for the cross coupling: Kochi, J. J. Org. Chem.1976, 41, 502
Bogdanovic: four-electron reduction, formal constitution [Fe(MgCl)2]n 1:1 mixture of alkene and alkane is formed from the Grignard reagent in the reduction of FeX2, Bogdanovic proposed a -hydride elimination followed by a reductive elimination as two of the elementary steps
1:1 mixture of alkene and alkane is formed from the Grignard reagent in the reduction of FeX2, Bogdanovic proposed a -hydride elimination followed by a reductive elimination as two of the elementary steps in the formation of [Fe(MgX)2]
Ferrate: 高铁酸盐 J. AM. CHEM. SOC. 2008, 130, 8773–8787
Masaharu Nakamura: Hideo Nagashima: J. AM. CHEM. SOC. 2009, 131, 6078–6079
Radical cyclization rate 1.0x105M-1S-1 Radical ring open rate 1.3x108M-1S-1
Possible catalytic cycle for the (TMEDA)FeAr2-catalyzed crosscoupling reaction.
features: (1) divalent iron (+II oxidation state), (2) neutral complex, (3) coordinatively unsaturated, (4) having sufficient spin density on the iron center. Masaharu Nakamura:J. AM. CHEM. SOC. 2010, 132, 10674–10676
Oxidative homo-coupling Cahiez: J. AM. CHEM. SOC. 2007, 129, 13788-13789
benzyl-, allyl-, or tertiary alkylzinc give low yields Angew. Chem. Int. Ed. 2009, 48, 2969 –2972
Cross-coupling based on C-H activation/C-C bond formation: Cheap iron and mild condition 0oC J. AM. CHEM. SOC. 2008, 130, 5858–5859
Yu, XQ: Angew. Chem. Int. Ed. 2008, 47, 8897 –8900 Lei AW: Angew. Chem. Int. Ed. 2010, 49, 2004 –2008