Transition‐Metal‐Catalyzed Acyloxylation: Activation of C(sp²)–H and C(sp³)–H Bonds

Abstract

In this review we present recent advances in C–H bond activation for transition‐metal‐catalyzed acyloxylation. This activation is a powerful method for the construction of C–O bonds in diverse compounds. Directed and non‐directed approaches are covered, with the emphasis on the role of directing groups in these transformations.

Stereoselective Sulfinyl Aniline‐Promoted Pd‐Catalyzed C−H Arylation and Acetoxylation of Aliphatic Amides

“…Finally, in order to extend the potential of the APS‐directed diastereoselective activation of aliphatic C−H bonds, we endeavored on developing a related direct C−O coupling (Scheme ) . Importantly, asymmetric C−O bond formation by means of C−H activation remains elusive .…”

Directed C−H Bond Oxidation of Bridged Cycloalkanes Catalyzed by Palladium(II) Acetate

“…To summarize the mechanistic investigation we have proven that the catalytic cycle can be divided in two consecutive steps: reversible C−H activation to palladacycle C2 and irreversible oxidation to complex C4 , which proceeds with retention of configuration. The nature of the oxidation step is not yet proven,,, (two plausible pathways are proposed: concerted demetalation–oxidation or oxidation of Pd II complexes to Pd IV ) (Figure ).…”

Ruthenium‐Catalyzed Regioselective Direct Ortho‐Acyloxylation of Azoarenes with Carboxylic Acids via C–H Bond Activation

“…1 7,150.9,149.1,144.3,142.8,141.9,141.46,130.4,129.6,129.3,127.3,123.9,122.9,117.5,21.9,21.6,21.5;MS (EI): m/z (%) = 344 (38) [M + ], 225 (22), 167 (10), 149 (17), 119 (100), 91 (39), 65 (21). Yield: 85 % (87 mg).…”

“…C 22 H 20 N 2 O 2 (344.41): calcd. 7, 150.8, 149.1, 141.4, 130.5, 130.4, 129.6, 128.1, 128.0, 127.3, 126.8, 123.9, 122.9, 29.1, 21.5, 21.4, 15. 4, 150.9, 145.1, 142.1, 140.1, 131.8, 129.5, 129.1, 129.0, 128.9, 127.9, 122.5, 122.3, 121.6, 121.4, 21.6, 21.4 (14), 139 (100), 119 (21), 111 (37), 91 (28). 1,142.7,142.0,141.4,132.5,129.6,127.2,124.0,122.9,121.9,117.5,113.84,55.5,21.5,21.4;MS (EI): m/z (%) = 360 (12) [M + ], 167 (21), 149 (31), 135 (100), 107 (21), 91 (27), 57 (28).…”

“…[17] The palladium-catalyzed ortho-alkoxylation and hydroxylation of aromatic azo compounds were described by Sun, [18] Chakraborti [19] and Joseph. [21] Most recently Li [22] and coworkers described the Rh III -catalyzed acyloxylation of various sp 2 C-H bonds with readily available carboxylic acids. [21] Most recently Li [22] and coworkers described the Rh III -catalyzed acyloxylation of various sp 2 C-H bonds with readily available carboxylic acids.…”