The aryl‐to‐vinyl nickel 1,4‐migration (1,4‐Ni migration) reaction has been reported for the first time. The generated alkenyl Ni species undergo a reductive coupling reaction with unactivated ...brominated alkanes affording a series of trisubstituted olefins. This tandem reaction exhibits mild conditions, a broad substrate scope, high regioselectivity, and excellent Z/E stereoselectivity. A series of controlled experiments have shown that the critical 1,4‐Ni migration process is reversible. In addition, the alkenyl nickel intermediates obtained after migration are highly Z/E stereoselective and do not undergo Z/E isomerization. The obtained trace isomerization products are caused by the instability of the product.
The 1,4‐nickel migration process from aryl to alkenyl groups is now reported for the first time. The alkenyl nickel intermediates generated by this highly stereoselective migration process can be coupled with brominated alkanes to form multisubstituted olefins. The current method provides a new and efficient approach for the synthesis of Z/E olefins with high stereoselectivity.
A novel base-mediated direct difluoroalkylation of 1,6-enynes involving a CF2 radical process has been developed. In the absence of metal catalysts, two different difluoroalkylated cyclization ...products have been synthesized with good functional group applicability and high stereoselectivity. Notably, the properties of a base have been shown to play a crucial role in the generation selectivity of this transformation.
An operationally simple radical difluoroalkylation/trifluoromethylation and alkynylation of unactivated alkenes under mild conditions has been developed. Through this protocol, a series of CF2/CF3‐ ...substituted linear alkynyl ketones were synthesized via a unique 1,2‐alkynyl radical migration. Notably, no transition‐ metal catalyst is needed in the developed reaction system, and excellent functional group compatibility was observed.
An efficient palladium‐catalyzed cyclization and polyfluorophenylation of γ,δ‐unsaturated polyfluorobenzoyl oxime ester via iminopalladation/polyfluorobenzoyloxy decarboxylation cascade reaction is ...developed. The protocol provides a practical and atom‐economical access to a broad scope of various polyfluorophenylated dihydropyrrole derivatives. The reaction effectively utilizes the polyfluorobenzoyloxy leaving group as polyfluorophenylated source for the first time, precluding the need of additional polyfluoroarene. This is the first example of the introduction of electron‐deficient arenes in the further transformation of Narasaka‐Heck‐type reaction. Additionally, the reaction is conducted in a short time.
Heck Cyclization: An efficient palladium‐catalyzed cyclization and polyfluorophenylation of γ,δ‐unsaturated polyfluorobenzoyl oxime ester via iminopalladation/polyfluorobenzoyloxy decarboxylation cascade reaction is developed. The protocol provides a practical and atom‐economical access to a broad scope of various polyfluorophenylated dihydropyrrole derivatives. The reaction effectively utilizes the C6F5COO leaving group as C6F5 source for the first time, precluding the need of additional polyfluoroarene. Additionally, the reaction is conducted in a short time.
Herein, we describe a novel and efficient photo-redox catalytic difluorinated ester radical addition/defluoroalkylation coupling reaction between trifluoroacetic acid derivatives and ...α-trifluoromethyl alkenes. A series of polyfluorinated compounds were synthesized by the selective cleavage of the single C–F bond in the trifluoromethyl (CF3) group enabled by the spin-center shift (SCS). The reaction is characterized by wide substrate scope and good functional group tolerance.
A copper-catalyzed radical cross-coupling of oxime esters and activated alkenes is accomplished for the synthesis of cyanoalkylsulfonylated oxindoles and cyanoalkyl amides via an aryl migration ...strategy. Specifically, the subsequent mechanism research indicates that the unique desulfonylation and sulfone addition processes were involved in the transformation. This transformation is identified as having good functional group applicability with two different quaternary stereocenter in a regioselective manner, which is controlled by the substituent group of the nitrogen.
Herein, we describe a novel and efficient photoredox catalytic radical addition/defluoroalkylation coupling reaction between primary amines and trifluoromethyl-substituted alkenes. A series of ...gem-difluoroalkenes were synthesized via C–N bond cleavage of α-3°, α-2°, and α-1° amines under visible light irradiation. This reaction is characterized by a broad substrate scope and good functional group tolerance.
This report describes the first example of palladium-catalyzed ortho-C–H glycosylation/ipso-alkenylation of aryl iodides, and the easily accessible glycosyl chlorides are used as a glycosylation ...reagent. The reaction is compatible with the functional groups of the substrates, and a series of C-aryl glycosides have been synthesized in good to excellent yield and with excellent diastereoselectivity. It is found that a cheap 5-norbornene-2-carbonitrile as a transient mediator can effectively promote this reaction. In addition, ipso-arylation and cyanation were also realized by the strategy.
We described a novel palladium-catalyzed domino procedure for the preparation of (hetero)aryl thio/selenoglycosides. Readily available (hetero)aryl iodides and easily accessible ...1-thiosugars/1-selenosugars are utilized as the substrates. Meanwhile, 10 types of sugars are quite compatible with this reaction with good regio- and stereoselectivity, high efficiency, and broad applicability (up to 89%, 53 examples). This method enables the straightforward formation of the C(sp2)–S/Se bond of (hetero)aryl thio/selenoglycosides.
Free radical cyclization has emerged as one of the most important reaction types, which is widely used in natural product synthesis, pharmaceutical chemistry, and materials science. This report ...described the combination of radical cyclization and ruthenium-catalyzed meta-selective C–H functionalization for the synthesis of arylpyrrolidone derivatives. This method exhibited the highly meta-site selectivity of the primary, secondary, and tertiary alkyl radicals formed by intramolecular addition. A wide spectrum of directing groups bearing diversified N-heterocycles performed well, including biologically active molecules. Density functional theory calculations provided a theoretical basis for the high meta-selectivity and the favored reaction pathway of an intramolecular cyclization.
