A remarkable transformation to realize ortho arylation of acetanilides via Pd(II)-catalyzed C−H functionalization with trialkoxyarylsinaes was demonstrated.

Scheme 4. Scope of the reaction with aryl aldehydes. Scheme 5. Scope of the reaction with other aromatic aldehydes. Scheme 6. Scope of the reaction with N,N-disubstituted formamides. 2.0 mL of ethyl acetate was used for 9 f. N.O = not obtained Angewandte Chemie 3233

Highly regioselective C-H functionalization/halogenation of acetanilides to produce ortho-haloacetanilides was catalyzed by Pd(OAc)2 and Cu(OAc) 2 with CuX2 as the halogen source.

Highly regioselective olefination of substituted N,N-dimethylbenzylamines was developed by tuning the acidity of reaction conditions based on analysis of their features. The ortho-functionalized N,N-dimethylbenzylamines were further transformed into 3-(2'-tolyl)propanoic acid and its derivatives under mild conditions. These two transformations could be combined into one pot, and 3-(2'-tolyl)propanoic acid and its derivatives were obtained in moderate to good yields. Mechanistic studies indicated that electrophilic attack on the phenyl ring by the Pd(II) ion assisted by the N,N-dimethylaminomethyl group was a key step during this catalytic transformation, which was controlled by the acidity of the reaction conditions.

No abstract

A seamless join: An efficient method to construct a C(sp2)C(sp2) bond has been developed by using a Suzuki–Miyaura‐type coupling of N‐alkyl acetanilides with boronic acids. The reaction was catalyzed by a PdII species and the CH bond activation was directed by the acetamino group (see scheme). This reaction offers a halogen‐free method to construct complicated structures.

A new tert-butyl peresters synthesis directly from aldehydes and TBHP was developed via Bu(4)NI-catalyzed aldehyde C-H oxidation. Mechanistic studies suggest that the protocol proceeds via a radical process. Combining the method with the Kharasch-Sosnovsky reaction offers a practical approach for the synthesis of allylic esters from simple aldehydes and alkenes via a two-step one-pot procedure.

The cleavage and functionalization of CÀH bonds is of fundamental interest for both academia and industry. Generally, the transformation relies on transition metals, [1] which are involved in four major approaches: 1) electrophilic activation of the C À H bond by a high-valent transition metal; 2) oxidative addition to the C À H bond by low-valent transition metals; 3) C À H bond activation by s-bond metathesis, and 4) insertion of a metal carbenoid/nitrenoid into the CÀ H bond. After extensive studies, transition-metal-catalyzed CÀH activation has arisen as an excellent synthetic method to build complex structures because it reduces prefunctionalization while improving atom economy and energy efficiency. However, the use of expensive metal catalysts and the problems involved in removing the residual metals from the final products, which is usually a difficult and tedious process, limits the practical applications of this strategy. The discovery of an efficient CÀH transformation that does not require a metal catalyst would be of great value. This strategy would eliminate the requirement to remove traces of metal from the final products and solve the problem of disposal of the metal catalyst from the reaction mixtures. Recently, several groups disclosed a variety of novel C À C bond formations by using CÀH activation under transition-metalfree conditions. [2,3] The cross-dehydrogenative coupling (CDC) reaction, beyond traditional cross-couplings, has been the object of increasing interest over the last ten years. However, transition-metal catalysts, such as iron and copper salts, were usually required to promote this transformation. [4,5]