Palladium-Catalyzed Cascade Arylation of Vinylogous Esters Enabled by Tris(1-adamantyl)phosphine

Total synthesis of (±)-mersicarpine following a 6-exo-trig radical cyclization

Described is a total synthesis of racemic mersicarpine from diethyl 4-oxopimelate. The synthetic route takes advantage of a 2-indolyl radical cyclization to construct the pyrido[1,2-a]indole scaffold bearing the all-carbon quaternary stereocenter.

Palladium-Catalyzed Site-Selective Arylation of α,β-Unsaturated Carbonyl Compounds through a Ligand-Controlled Strategy

Palladium-catalyzed direct arylation of α,β-unsaturated carbonyl compounds is an efficient and attractive strategy to access arylated α,β-unsaturated carbonyl compounds through the construction of carbon–carbon bonds. This reaction has several challenges, especially in terms of the control of regioselectivity between α- and γ-arylation and the selectivity for monoarylation and multiple arylation. Herein, we discuss the recent development of γ-arylation of α,β-unsaturated carbonyl compounds and present the ligand-controlled, site-selective α- and γ-arylation of α,β-unsaturated carbonyl ketones with (hetero)aryl halides. The site selectivity of the reaction is switchable by simply changing the phosphine ligand.

1 Introduction

2 Reaction Development and Mechanistic Investigation

3 Conclusion and Outlook

Palladium-Catalyzed Direct γ-C(sp3)-H Arylation of β-Alkoxy Cyclohexenones: Reaction Scope and Mechanistic Insights

Direct γ-C(sp3)-arylation of unactivated electron-rich enones is a long-standing challenge. Herein, we report a mild Pd-catalyzed method for direct γ-C(sp3)-arylation of various unactivated β-alkoxy cyclohexenones. The method is not only...

Haloarene-guided cascade arylation of cyclic vinylogous esters under palladium catalysis

A method is presented for the synthesis of diaryl cyclic vinylogous esters. The sequence of C(sp³)-H arylation events is programed under the differentiated reactivity of the aryl halides, and the optimized reaction system is effectively diverted from producing dihomo-arylated products. The site selectivity of the second arylation is notably modulated by the substitution pattern of the substrates.

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

α-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.

Palladium-catalyzed α-arylation of indolin-3-ones

A method for the catalytic α-arylation of indolin-3-ones was developed. The catalytic system comprising Pd(dba)₂ and PAd₃ was found to be optimal for the transformation. The protocol features broad functional group compatibility in that a range of arylated indoxyl derivatives bearing a fully substituted carbon center was synthesized with high efficiency. A preliminary bioassay study revealed that the selected indole-substituted indolin-3-ones exhibit favorable cytotoxic activities against HCT-116 cancer cell line.