Xuesong Wu

Nickel-Catalyzed Site-Selective Alkylation of Unactivated C(sp3)–H Bonds

The direct alkylation of unactivated sp(3) C-H bonds of aliphatic amides was achieved via nickel catalysis with the assist of a bidentate directing group. The reaction favors the C-H bonds of methyl groups over the methylene C-H bonds and tolerates various functional groups. Moreover, this reaction shows a predominant preference for sp(3) C-H bonds of methyl groups via a five-membered ring intermediate over the sp(2) C-H bonds of arenes in the cyclometalation step.

Copper‐Catalyzed Site‐Selective Intramolecular Amidation of Unactivated C(sp3)H Bonds

The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp(3) C-H bond functionalization process. The reaction favors predominantly the C-H bonds of β-methyl groups over the unactivated methylene C-H bonds. Moreover, a preference for activating sp(3) C-H bonds of β-methyl groups, via a five-membered ring intermediate, over the aromatic sp(2) C-H bonds was also observed in the cyclometalation step. Additionally, sp(3) C-H bonds of unactivated secondary sp(3) C-H bonds could be functionalized by favoring the ring carbon atoms over the linear carbon atoms.

Cobalt-catalysed site-selective intra- and intermolecular dehydrogenative amination of unactivated sp 3 carbons

Cobalt-catalysed sp2 C–H bond functionalization has attracted considerable attention in recent years because of the low cost of cobalt complexes and interesting modes of action in the process. In comparison, much less efforts have been devoted to the sp3 carbons. Here we report the cobalt-catalysed site-selective dehydrogenative cyclization of aliphatic amides via a C–H bond functionalization process on unactivated sp3 carbons with the assistance of a bidentate directing group. This method provides a straightforward synthesis of monocyclic and spiro β- or γ-lactams with good to excellent stereoselectivity and functional group tolerance. In addition, a new procedure has been developed to selectively remove the directing group, which enables the synthesis of free β- or γ-lactam compounds. Furthermore, the first cobalt-catalysed intermolecular dehydrogenative amination of unactivated sp3 carbons is also realized.

Direct Aerobic Carbonylation of C(sp2)–H and C(sp3)–H Bonds through Ni/Cu Synergistic Catalysis with DMF as the Carbonyl Source

The direct carbonylation of aromatic sp(2) and unactivated sp(3) C-H bonds of amides was achieved via nickel/copper catalysis under atmospheric O2 with the assistance of a bidentate directing group. The sp(2) C-H functionalization showed high regioselectivity and good functional group compatibility. The sp(3) C-H functionalization showed high site-selectivity by favoring the C-H bonds of α-methyl groups over those of the α-methylene, β- or γ-methyl groups. Moreover, this reaction showed a predominant preference for functionalizing the α-methyl over α-phenyl group. Mechanistic studies revealed that nickel/copper synergistic catalysis is involved in this process.

Nickel‐Catalyzed Site‐Selective Amidation of Unactivated C(sp3)H Bonds

Intramolecular dehydrogenative cyclization of aliphatic amides was achieved on unactivated sp(3) carbon atoms by a nickel-catalyzed CH bond functionalization process with the assistance of a bidentate directing group. The reaction favors the CH bonds of β-methyl groups over the γ-methyl or β-methylene groups. Additionally, a predominant preference for the β-methyl CH bonds over the aromatic sp(2) CH bonds was observed. Moreover, this process also allows for the effective functionalization of benzylic secondary sp(3) CH bonds.

Copper-Promoted Site-Selective Acyloxylation of Unactivated C(sp3)H Bonds

The site-selective acyloxylation of aliphatic amides was achieved via a copper-promoted C(sp(3))-H bond functionalization process directed by a bidentate ligand. The reaction showed a great preference for activating C-H bonds of β-methyl groups over those of γ-methyl and unactivated methylene groups.

Correction to "Nickel-catalyzed site-selective alkylation of unactivated C(sp3)-H bonds".

Page 1791. On the basis of results of deuterium labeling studies described in the text and Supporting Information, the step from nickel complex A to intermediate B in Scheme 1 might be an irreversible process. Therefore, the text describing Scheme 1 should be corrected to read, “Coordination of amide 1 to a Ni species followed by a ligand exchange process under basic conditions generates nickel complex A, which gives rise to the intermediate B via a cyclometalation process.” Correspondingly, Scheme 1 should be corrected as follows: