Pd(II)-Catalyzed Intermolecular Arylation of Unactivated C(sp3)–H Bonds with Aryl Bromides Enabled by 8-Aminoquinoline Auxiliary

Palladium-catalyzed direct β-arylation of ketones with diaryliodonium salts: a stoichiometric heavy metal-free and user-friendly approach

We herein report a new protocol for the Pd-catalyzed β-arylation of ketones without stoichiometric heavy metals. Widely accessible diaryliodonium salts are used as both the oxidant and aryl source. This tandem redox catalysis merges ketone dehydrogenation and conjugate addition without an additional oxidant or reductant. This transformation features the use of a unique bis-N-tosylsulfilimine ligand and the combination of potassium trifluoroacetate/trifluoroacetic acid to maintain an appropriate acidity of the reaction medium. The reaction tolerates both air and moisture, and shows a broad substrate scope. Kinetics studies, along with filtration and poisoning tests, support the involvement of palladium nanoparticles in the catalysis.

Practical synthesis of anti-β-hydroxy-α-amino acids by Pd(II) -catalyzed sequential C(sp(3) )-H functionalization

An improved and practical procedure for the stereoselective synthesis of anti-β-hydroxy-α-amino acids (anti-βhAAs), by palladium-catalyzed sequential C(sp(3) )-H functionalization directed by 8-aminoquinoline auxiliary, is described. followed by a previously established monoarylation and/or alkylation of the β-methyl C(sp(3) )-H of alanine derivative, β-acetoxylation of both alkylic and benzylic methylene C(sp(3) )-H bonds affords various anti-β-hydroxy-α-amino acid derivatives. As an example, the synthesis of β-mercapto-α-amino acids, which are highly important to the extension of native chemical ligation chemistry beyond cysteine, is described. The synthetic potential of this protocol is further demonstrated by the synthesis of diverse β-branched α-amino acids. The observed diastereoselectivities are strongly influenced by electronic effects of aromatic AAs and steric effects of the linear side-chain AAs, which could be explained by the competition of intramolecular C-OAc bond reductive elimination from Pd(IV) intermediates vs. intermolecular attack by an external nucleophile (AcO(-) ) in an SN 2-type process.

Nickel-catalyzed synthesis of diarylsulfides and sulfones via C–H bond functionalization of arylamides

The sulfenylation and sulfonylation of (sp²)C–H bonds of benzamides were achieved with the aid of a bidentate directing group.

Transition metal-catalyzed direct remote C–H functionalization of alkyl groups via C(sp3)–H bond activation

This review is focused on the recent advances in the transition metal-catalyzed direct remote C–H-functionalization of alkyl groups via C(sp³)–H bond activation. In general, carboxamide/ester-chelated β-functionalization reactions are summarized.

NIS/CHP-mediated reaction of isocyanides with hydrazones: access to aminopyrazoles

A NIS/CHP-mediated reaction of isocyanides with hydrazones to construct aminopyrazoles has been developed.

Palladium-catalyzed unactivated β-methylene C(sp3)–H bond alkenylation of aliphatic amides and its application in a sequential C(sp3)–H/C(sp2)–H bond alkenylation

A palladium(ii)-catalyzed β-methylene C(sp³)–H bond alkenylation of acyclic aliphatic amides with alkenyl halides has been developed. Solvent effect-promoted sequential C(sp³)–H bond alkenylation and C(sp²)–H bond alkenylation has also been studied.

Transition metal-catalyzed C–H bond functionalizations by the use of diverse directing groups

In this review, a summary of transition metal-catalyzed C–H activation by utilizing the functionalities as directing groups is presented.

Pd(ii)-Catalyzed arylation of unactivated methylene C(sp3)–H bonds with aryl halides using a removable auxiliary

Pd(ii)-catalyzed arylation of methylene C(sp³)–H bonds with ArBr directed by our newly developed PIP auxiliary was reported.