α-C(sp3)-H Arylation of Cyclic Carbonyl Compounds

Abstract

Abstractα-C(sp3)-H arylation is an important type of C-H functionalization. Various biologically significant natural products, chemical intermediates, and drugs have been effectively prepared via C-H functionalization. Cyclic carbonyl compounds comprise of cyclic ketones, enones, lactones, and lactams. The α-C(sp3)-H arylation of these compounds have been exhibited high efficiency in forming C(sp3)-C(sp2) bonds, played a crucial role in organic synthesis, and attracted majority of interests from organic and medicinal communities. This review focused on the most significant advances including methods, mechanism, and applications in total synthesis of natural products in the field of α-C(sp3)-H arylations of cyclic carbonyl compounds in recent years.

Allylsilane as a versatile handle in photoredox catalysis

“…The polarity of the carbonyl group renders this center an attractive and extremely reactive site, which could facilitate various reactions in organic synthesis to construct the most fundamental C-C bond. 46 This part of the context gives a detailed description of such a type of reactivity for the formation of the C-C bond using allylsilanes as a precursor in visible-light photoredox catalysis. In early examples, employing allylsilane photo-allylation at the carbonyl carbon atom of N-methylarene dicarboximide was reported by Kubo and coworkers in 1986.…”

Insights into the Mechanism and Regioselectivity of Palladium-Catalyzed Arylation of α,β-Unsaturated Ketones

“…[1][2][3] Palladium-catalyzed arylation of carbonyl compounds has been dramatically developed in the past two decades, as it provides a convenient method for constructing C-C bonds. [4][5][6] In 1997, the first Pd-catalyzed direct α-arylation of ketones with aryl halides was almost simultaneously reported by Buchwald and Hartwig, 7,8 who established a milestone in this field of research. Since then, more and more coupling reactions between aryl halides or pseudohalides 9 and carbonyl compounds including ketones, aldehydes, esters, amides, lactones, 10 lactams 11 and cyclic ketones by the catalysis of palladium have been discovered, 4 and the applications of these reactions in the synthesis were gradually developed.…”

Palladium-catalyzed direct γ-C(sp3)–H arylation of β-alkoxy cyclohexenones: reaction scope and mechanistic insights

“…1 So far, Pd-catalyzed C(sp 3 )–H functionalization has been highly developed and resulted in a myriad of achievements. 2 Therein, the Buchwald–Hartwig–Miura (BHM) arylation 3 facilitates direct installation of α-aryl fragments in various ketones, and has become an important strategy in the total synthesis of natural products and drug development. 4 However, as an important complement to BHM arylation, Pd-catalyzed γ-C(sp 3 )–H arylation of cyclic enones has not been investigated well, not only because of the lower acidities and higher bond-dissociation energies of γ-C(sp 3 )–H bonds compared to α′-C(sp 3 )–H bonds but also because of the bigger ring tension of the cyclic enone.…”