Photo-Thermo-Mechanochemical Approach to Synthesize Quinolines via Addition/Cyclization of Sulfoxonium Ylides with 2-Vinylanilines Catalyzed by Iron(II) Phthalocyanine

Lithium Bromide-Promoted Formal C(sp3)-H Bond Insertion Reactions of β-Carbonyl Esters with Sulfoxonium Ylides to Synthesize 1,4-Dicarbonyl Compounds

A LiBr-promoted formal C(sp3)-H bond insertion reaction between β-carbonyl esters and sulfoxonium ylides is established. This practical reaction has a wide range of substrate scope for both β-carbonyl esters and sulfoxonium ylides to give a variety of 1,4-dicarbonyl compounds with 43-94% yields. The reaction features transition-metal-free reaction conditions and exclusive C-alkylation chemselectivity. The use of bench-stable sulfoxonium ylides overcomes previous methods that require transition metal as catalysts and unstable diazo compounds or toxic haloketones as alkylation reagents.

Cu-Catalyzed Carbocyclization for General Synthesis of N-Containing Heterocyclics Enabled by BrCF2COOEt as a C1 Source

A practical and efficient copper-catalyzed carbocyclization of 2-functionalized anilines with ethyl bromodifluoroacetate has been developed. Ethyl bromodifluoroacetate is employed as the C1 source via quadruple cleavage in this transformation. This reaction can afford a variety of N-containing heterocyclics with satisfactory yields and excellent functional group compatibility.

Identification of novel 3-aryl-1-aminoisoquinolines-based KRASG12C inhibitors: Rational drug design and expedient construction by CH functionalization/annulation

Developing a synthetic methodology to expediently construct a specific drug scaffold with the desired biological activity remains challenging. Herein, we describe a work on rational application of a synthetic methodology in the synthesis of KRASG12C inhibitors. Novel KRASG12C inhibitors were initially designed with 1-amino-3-aryl isoquinoline scaffold using structure-based drug design strategy. A ruthenium-catalyzed direct monoCH functionalization/annulation cascade reaction of amidines and sulfoxonium ylides was then developed with high versatility of substrates and good tolerance for polar functional groups. By using this reaction, the target compounds 1-amino-3-aryl isoquinolines were facilely prepared. Further in vitro tests led to identification of two novel lead compounds with KRASG12C inhibitory activity.

[Cp*IrCl2]2-Catalyzed Amidocarbonation of Olefins with Sulfoxonium Ylides toward Functionalized Isoindolin-1-ones

A [Cp*IrCl2]2-catalyzed amidocarbonation of olefins with sulfoxonium ylides has been developed to generate diverse biologically important isoindolin-1-ones in high efficiency under mild reaction conditions. Mechanism studies indicated that this cascade reaction was triggered by amino-iridation of the olefin unit to generate iridacycle, followed by formal migratory insertion with sulfoxonium ylides. This newly developed method features broad substrate scopes and operational simplicity.

Cu-Catalyzed Decarboxylative Annulation of N-Phenylglycines with Maleimides: Synthesis of 1H-Pyrrolo[3,4-c]quinoline-1,3(2H)-diones

A novel protocol for the construction of functionalized 1H-pyrrolo[3,4-c]quinoline-1,3(2H)-diones (PQLs, 3) from N-phenylglycines and maleimides was developed. The cascade reaction was enabled by heating a mixture of the two substrates in the presence of di-tert-butyl peroxide (DTBP) as an oxidant and anhydrous CuBr as a catalyst in chlorobenzene. Consequently, a diverse series of PQLs 3 were synthesized in moderate-to-good yields (43-73%). The synthesis of the PQLs was enabled via a one-pot cascade reaction that proceeded through subsequent oxidative decarboxylation, 1,2-addition, intramolecular cyclization, tautomerization, and aromatization reactions. This protocol can be used for the synthesis of functionalized PQLs via a one-pot oxidative decarboxylation annulation reaction rather than through a series of multistep reactions, making it suitable for both combinatorial and parallel syntheses of PQLs.

Recent Advances in Alkenyl sp2 C-H and C-F Bond Functionalizations: Scope, Mechanism, and Applications

Alkenes and their derivatives are featured widely in a variety of natural products, pharmaceuticals, and advanced materials. Significant efforts have been made toward the development of new and practical methods to access this important class of compounds by selectively activating the alkenyl C(sp²)-H bonds in recent years. In this comprehensive review, we describe the state-of-the-art strategies for the direct functionalization of alkenyl sp² C-H and C-F bonds until June 2022. Moreover, metal-free, photoredox, and electrochemical strategies are also covered. For clarity, this review has been divided into two parts; the first part focuses on currently available alkenyl sp² C-H functionalization methods using different alkene derivatives as the starting materials, and the second part describes the alkenyl sp² C-F bond functionalization using easily accessible gem-difluoroalkenes as the starting material. This review includes the scope, limitations, mechanistic studies, stereoselective control (using directing groups as well as metal-migration strategies), and their applications to complex molecule synthesis where appropriate. Overall, this comprehensive review aims to document the considerable advancements, current status, and emerging work by critically summarizing the contributions of researchers working in this fascinating area and is expected to stimulate novel, innovative, and broadly applicable strategies for alkenyl sp² C-H and C-F bond functionalizations in the coming years.

Unexpected Copper-Catalyzed Cascade Reaction of 1,6-Enynes with Sulfoxonium Ylides

An unprecedented copper-catalyzed cascade reaction of 1,6-enynes with sulfoxonium ylides is reported, providing a series of structurally intriguing 2,3-disubstituted indolines bearing a conjugated dienone functionality at the 3-position in moderate to excellent yields with good chemo-, regio-, and diastereoselectivities under mild reaction conditions. Importantly, sulfoxonium-ylide-derived copper-carbene herein exhibits quite different reactivity from that of diazo copper-carbene. A rational mechanism, an initial ammonium ylide rather than allene formation, is proposed.

One-pot synthesis of 3-trifluoromethylbenzo[b][1,4]oxazines from CF3-imidoyl sulfoxonium ylides with 2-bromophenols

A one-pot two-step fashion for the synthesis of 3-trifluoromethyl-1,4-benzoxazines from CF3-imidoyl sulfoxonium ylides and 2-bromophenols via lithium-bromide-promoted O–H insertion of sulfoxonium ylides and annulation has been demonstrated.