Iron‐Catalyzed Oxidative Radical Cross‐Coupling/Cyclization between Phenols and Olefins

Iron Catalysis in Organic Synthesis

“…721 Thus, electron-rich phenols reacted with styrenes in the presence of iron(III) chloride as catalyst and DDQ as oxidant to afford dihydrobenzofurans in high yields. The reaction probably follows a radical pathway.…”

Carbon‐Centered Radical Addition to C=X Bonds for C−X Bond Formation

“…In 2013, Lei and co-workersr eported an iron-catalyzed oxidative radical cross-coupling/cyclization between phenols and alkenes. [22] In the presence of FeCl 3 as the catalysta nd 2,3-dichloro-5,6-dicyano-1,4-benzoqinone (DDQ) as the effective oxidant, different electron-rich phenols and variousk inds of alkenes could be transformed into the desired dihydrobenzofurans in good yields under ambient temperature (Scheme 9). Detailed EPR spectroscopy experimentsshowed that DDQ reacted with phenolt op roduce ar adicala nd wasi tselfr educed to form the HDDQ radical.…”

Iron‐Catalyzed C(sp2)H and C(sp3)H Methylations of Amides and Anilides

“…[16] AnilideC À Hf unctionalization Thus far,a ll organometallici ron-catalyzed CÀCf orming CÀH functionalizations have been severely restricted to the use of 1) strongly-coordinating, but difficult to remove or modify nitrogen donors, such as pyridines, or 2) bidentate amide auxiliaries. [10] Thus, despite of the practical importance of substituted aniline derivatives, their syntheses by chelation-assisted ironcatalyzed CÀHf unctionalization have, to our knowledge, provene lusive. Therefore, we were particularly delightedt o find that easily accessible TA-anilide 10 set the stage for the iron-catalyzed CÀHm ethylation (Scheme 5).…”

“…[6] Particularly,C À Hm ethylations have, as of yet, been almoste xclusively achieved with expensive 4d transition-metal catalysts [7] based on rhodium or palladium complexes. [8] Although, in recent years, considerable progress was realized throughi ron-catalyzed CÀHf unctionalizations, as reported by Nakamura/Ilies, Yoshikai, our group, and Cook, [9,10] ag eneral protocol for iron-catalyzed CÀHm ethylations has proven to be elusive. Within our program on the use of earth-abundant base metalsf or CÀHa ctivation, [11,12] we have developed aw idely applicable iron-catalyzed CÀHm ethylation protocol through triazole [13] assistance.…”