Iron-Catalyzed C–H Borylation of Arenes

Abstract

Well-defined iron bis(diphosphine) complexes are active catalysts for the dehydrogenative C-H borylation of aromatic and heteroaromatic derivatives with pinacolborane. The corresponding borylated compounds were isolated in moderate to good yields (25-73%) with a 5 mol% catalyst loading under UV irradiation (350 nm) at room temperature. Stoichiometric reactivity studies and isolation of an original trans-hydrido(boryl)iron complex, Fe(H)(Bpin)(dmpe)2, allowed us to propose a mechanism showing the role of some key catalytic species.

Direct Functionalization of C−H Bonds by Iron, Nickel, and Cobalt Catalysis

“…The group of Ackermann, another key player in the field of non‐precious‐metal‐catalyzed C−H activation, presented a TAM (triazoledimethylmethyl)‐assisted methylation with in situ formed zinc‐organyls . Darcel and co‐workers recently demonstrated the formation of arylboronate esters 14 via iron‐catalyzed C−H activation (Scheme D) . Despite the general interest in this class of compounds for their application in Suzuki–Miyaura cross‐coupling reactions, elegant catalytic processes for their preparation are sparse.…”

“…[20] Darcel and co-workersr ecently demonstrated the formation of arylboronate esters 14 via iron-catalyzed CÀHa ctivation (Scheme 2D). [21] Despitet he general interest in this class of compounds for their application in Suzuki-Miyaura cross-coupling reactions, elegant catalytic processes for their preparationa re sparse. [Fe(Me) 2 (dmpe) 2 ]( dmpe = 1,2bis(dimethylphosphino)ethane) presumably inserts in the C(sp 2 )ÀHb ond of av ariety of aromatics ubstrates 13 with further transformation to the corresponding boronate esters.…”

Direct synthesis of dicarbonyl PCP-iron hydride complexes and catalytic dehydrogenative borylation of styrene

“…5i-k, 8 Based on our interest in iron catalysis involving hydroboranes, namely hydroboration of alkenes, 12d C-H borylation of arenes, 18 and CO 2 functionalization, 19 we decided to test the newly prepared complexes in the reaction of styrene with pinacolborane (HBpin). 5i-k, 8 Based on our interest in iron catalysis involving hydroboranes, namely hydroboration of alkenes, 12d C-H borylation of arenes, 18 and CO 2 functionalization, 19 we decided to test the newly prepared complexes in the reaction of styrene with pinacolborane (HBpin).…”

New Class of Hydrido Iron(II) Compounds with cis‐Reactive Sites: Combination of Iron and Diphosphinodithio Ligand

“…Hydridoi ron(II) complexes with phosphine-based tetradentate ligands( L 4 )c onstitute an important family in iron catalysis chemistry. [1][2][3] They serve as catalystso rh ave been postulated as intermediates in many iron-catalyzed processes, such as CO 2 hydrogenation, [4] formic acid dehydrogenation, [5] transfer hydrogenation, [6] and N 2 activationreactions. [7] For ah ydrido iron(II) complex, such as [HFeL 4 X] n + (n = 0w ith X = H, Cl; n = 1w ith X = MeCN, CO, or H 2 ), L 4 can coordinate in unfolded and folded modes.I na nu nfoldedm ode, L 4 is coordinated to the iron center in ap lanar arrangement, which results in H À and Xl igandsg enerally trans to one another in an octahedral geometry.…”