Photochemical Heck benzylation of styrenes catalyzed by Na[FeCp(CO)2]

Waldhart, Greyson W.; Mankad, Neal P.

doi:10.1016/j.jorganchem.2014.12.033

Cited by 15 publications

(9 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is interesting to note that previously such reactions between [Fp]and aryl halides were considered impossible. [37][38][39] Conventional methods for preparing FpAr complexes required presence of both a Pd catalyst and a Cu mediator to facilitate transmetallation between FpI (4) and aryl-zinc, -magnesium, -tin, or -boron reagents (Scheme 3). With our new method, there is no such need for any catalyst or another organometallic reagent beyond KFp.…”

Section: Resultsmentioning

confidence: 99%

“…At first, we decided to achieve such a catalytic transformation using 20% loading of KFp as a catalyst and a UV lamp as a source of power that makes CO dissociate from Fe, in a manner similar to a previous paper from our group. 37 However, we observed only traces of the target E-4styrylbenzonitrile 7a (Table 2, Entry 1). Increasing the amount of styrene to 5 eq.…”

Section: Fe-promoted Heck-type Coupling Of Aryl Fluorides With Alkenesmentioning

confidence: 88%

See 1 more Smart Citation

Fe-Promoted C-F Activation of Aryl Fluorides Enables Heck-Type Coupling with Alkenes and One-Pot Synthesis of Indenes

Radzhabov

Mankad

2023

Preprint

View full text Add to dashboard Cite

Metal-mediated aryl fluoride activation presents challenges because of the thermodynamically robust C-F bond but also provides opportunities to develop C-C coupling reactions with this unconventional electrophile. Here, we report that the metallanucleophile, K[CpFe(CO)2] (KFp), is readily arylated by aryl fluorides to provide CpFe(CO)2Ar (FpAr) complexes at ambient conditions in the absence of any catalyst, contrary to previous literature reports. This C-F activation likely proceeds by a SNAr mechanism rather than the more common oxidative addition pathway for metal-mediated C-F cleavage. Facile access to FpAr derivatives has enabled further development of Fe-promoted coupling reactions of aryl fluorides with alkenes and alkynes. Under stoichiometric Fe conditions, the first documented examples of Heck-type coupling reactions with aryl fluoride electrophiles are reported herein. Various aryl fluorides were found to couple with olefins to provide E-alkene products; aliphatic derivatives unexpectedly underwent reduction to 1,2-disubsituted ethane products to varying extents. Aryl fluorides were also found to couple with 5-decyne to yield indene derivatives in a one-pot manner; indeneone and indanone products were also observed in selected cases. A mechanistic investigation to identify the apparently potent hydride donor generated under these conditions was conducted, leading to a mechanistic hypothesis involving the intermediacy of metal carbonyl-capped, triple-decker ferrocene compounds as reductants. Despite the involvement of these diiron intermediates limiting stoichiometric product yields, the observed C-C coupling reactions expand the limits of organofluorine chemistry.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Fe-promoted Heck-type Coupling Of Aryl Fluorides With Alkenesmentioning

confidence: 88%

Fe-Promoted C-F Activation of Aryl Fluorides Enables Heck-Type Coupling with Alkenes and One-Pot Synthesis of Indenes

Radzhabov

Mankad

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In 2015, the Fe-catalyzed Heck reaction of benzyl chlorides 175 under UV irradiation was reported by Mankad (Scheme 33). 70 The authors favored a classical Heck reaction mechanism for this transformation, where UV irradiation promoted the CO dissociation to reveal reactive, coordinatively unsaturated Fe-containing intermediates. A radical-type process was considered to be an unproductive pathway under these conditions, competing with the Heck reaction and leading to decomposition.…”

Section: Other Metals In Heck-type Reactionsmentioning

confidence: 99%

Transition-Metal-Catalyzed Alkyl Heck-Type Reactions

Kurandina¹,

Chuentragool²,

Gevorgyan

2019

Synthesis

View full text Add to dashboard Cite

The Heck reaction is one of the most reliable and useful strategies for the construction of C–C bonds in organic synthesis. However, in contrast to the well-established aryl Heck reaction, the analogous reaction employing alkyl electrophiles is much less developed. Significant progress in this area was recently achieved by merging radical-mediated and transition-metal-catalyzed approaches. This review summarizes the advances in alkyl Heck-type reactions from its discovery early in the 1970s up until the end of 2018.1 Introduction2 Pd-Catalyzed Heck-Type Reactions2.1 Benzylic Electrophiles2.2 α-Carbonyl Alkyl Halides2.3 Fluoroalkyl Halides2.4 α-Functionalized Alkyl Halides2.5 Unactivated Alkyl Electrophiles3 Ni-Catalyzed Heck-Type Reactions3.1 Benzylic Electrophiles3.2 α-Carbonyl Alkyl Halides3.3 Unactivated Alkyl Halides4 Co-Catalyzed Heck-Type Reactions5 Cu-Catalyzed Heck-Type Reactions6 Other Metals in Heck-Type Reactions7 Conclusion

show abstract

“…74 Mankad and coworkers discovered that this system could be manipulated for catalytic applications by employing UV irradiation to drive the catalytic reaction (Scheme 31b). 75 By using the anionic complex 34, the group was successful in achieving an iron-catalysed Heck reaction that was E-selective. With an excess of olefin, and under UV irradiation to induce CO dissociation, the desired cross coupling product was produced in moderate yields along with an olefin migration product.…”

Section: Heckmentioning

confidence: 99%

“…74 (b) A modification of 33 for catalytic purposes in which benzyl chlorides were successfully coupled with styrene in the presence of 34 in an E-selective fashion. 75 where (see above). Additionally, Nakamura has employed in situ generated organoaluminium reagents for iron-catalysed cross coupling that were formed as a result of hydro-or carboalumination of alkynes.…”

Section: Additional Variationsmentioning

confidence: 99%