Pd(II)-Catalyzed C-H Acylation of (Hetero)arenes—Recent Advances

Abstract

Di(hetero)aryl ketones are important motifs present in natural products, pharmaceuticals or agrochemicals. In recent years, Pd(II)-catalyzed acylation of (hetero)arenes in the presence of an oxidant has emerged as a catalytic alternative to classical acylation methods, reducing the production of toxic metal waste. Different directing groups and acyl sources are being studied for this purpose, although further development is required to face mainly selectivity problems in order to be applied in the synthesis of more complex molecules. Selected recent developments and applications are covered in this review.

Exploration of C‐H Activation Strategies in Construction of Functionalized 2‐Aryl Benzoazoles: A Decisive Review

“…Palladium‐catalyzed acylation reaction is one of the versatile approaches for the synthesis of aryl ketones. Various acylating agents such as acids, aldehydes, toluenes and benzyl alcohols (Figure 3) have surfaced with each holding an advantage over the other and have been pondered for their reactivities and utility in C−H functionalization [22c] …”

Pd(II)‐Catalyzed Chelation‐Induced C(sp2)‐H Acylation of (Hetero)Arenes Using Toluenes as Aroyl Surrogate

“…In the same year, another minireview by Wu represents acylations of heteroarenes using diverse acyl sources where toluenes are also highlighted as one of the aroyl surrogates [21b] . In the last year, Lete and co‐workers had published a review where mainly benzaldehydes and α‐oxocarboxylic acids have been emphasized with only two articles of toluenes in Pd(II)‐catalyzed C−H acylation of (hetero)arenes [21c] . It is pertain to mention that significant developments have been made beyond 2015 in this area using toluene as the aroyl surrogate that warrants a fresh review on this topic.…”

Late-Stage C–H Acylation of Tyrosine-Containing Oligopeptides with Alcohols

“…18 Accordingly, if EtOH is in situ transformed into MeCHO in the presence of TBHP, 22 the reaction mechanism should be akin to those of related acylations with aldehydes described in the literature. 18 , 21 The high selectivity toward the monoacetylation could be due to the lower reactivity of EtOH in comparison to the corresponding aldehyde.…”