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This review summarizes the state-of-the-art in transition metal-catalyzed asymmetric alkylation of heteroarenes using alkenes (covering literature from 2000 to late 2021). Based on elementary reactions on metals for substrate activation, these reactions are broadly classified in several categories: (A) concerted oxidative addition of heteroaryl C–H bonds on rhodium(I) and iridium(I), (B) ligand-to-ligand hydrogen transfer (LLHT) on low-valent 3d metal complexes of nickel and cobalt, (C) different ways for deprotonation of heteroaryl C–H bonds by late transition metal complexes, especially palladium, including electrophilic aromatic substitution and a related mechanism, base-assisted intramolecular electrophilic substitution, concerted and nonconcerted metalation deprotonation, (D) σ-bond metathesis by d0 early transition metal complexes, (E) electrophilic activation of olefins by Pd(II), Pt(II) and Au(I), and (F) metal hydride insertion of aryl olefins and dienes. The demand to achieve enantiocontrol in the heteroarylation reactions has also driven innovation in chiral ancillary ligands, exemplified by extremely bulky, chiral N-heterocyclic carbenes for nickel catalysts, bulky monodentate oxazolines for Wacker-type reactions and chiral cyclopentadienyl ligands for half-sandwich complexes of scandium. [ABSTRACT FROM AUTHOR]

Nickel-catalyzed Heck reaction of cycloalkenes delivers unusual conjugated arylated isomers. Nickel(0) catalysts ligated by chelating dialkylphosphines effectively activate not only aryl triflates as electrophiles, but also less reactive aryl mesylates, tosylates and pivalates. The omission of bases allows nickel hydride species to exist long enough to perform in situ olefin isomerization of initial Heck adducts. [ABSTRACT FROM AUTHOR]

We report a green synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives which are of potential value in medicinal chemistry. We are able to access spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives via a Cu(OTf)2-catalyzed or Cu(OTf)2/Rh2(OAc)4-cocatalyzed multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate. The reaction can be accomplished in good to excellent yields (60–99%), and the structure of products 6a and 6k was supported by X-ray crystallography. The catalyst Cu(OTf)2 can be recycled 4 times without a sharp loss of the yield of 6a. 6q can be easily synthesized in gram scale. In brief, the reaction is characterized by step economy, a harmless solvent, and a recyclable catalyst. [ABSTRACT FROM AUTHOR]

A Pd(ii)-catalyzed formal [4+1] cycloaddition of aryl diazoacetates and aryl propargyl alcohols is reported to afford 2,5-dihydrofuran derivatives as the dominant product over other traditional ones. The auto-tandem catalytic process is proposed to occur via Pd(ii)-catalyzed intermolecular oxonium ylide formation and subsequent intramolecular trapping of the ylide with Pd(ii)-activated alkynes. [ABSTRACT FROM AUTHOR]