Alkenyl Acids Research Articles

Conversion of Carboxylic Acids to Sulfonamide Bioisosteres via Energy Transfer Photocatalysis.

More than 450 drugs containing a carboxylic acid functional group have been marketed worldwide. Herein, we report a concise and environmentally friendly organic photoinduced protocol for the interconversion of carboxylic acids into their bioisosteres. With this strategy, a variety of substrates, including alkyl, (hetero)aryl, and alkenyl acids, as well as various biologically relevant acids are successfully converted into primary sulfonamides.

Photo‐Induced Oxyamination of Alkenyl Acids towards Amino Lactones

AbstractPhoto‐induced sulfonylamidation/lactonization of alkenyl acids with N‐sulfonylaminopyridinium salts is demonstrated to access sulfonamidylated lactones under mild and metal‐free conditions. This reaction features a broad substrate scope, good functional group tolerance and easy operation, providing a simple and efficient protocol for the synthesis of sulfonamidylated lactones.

Paired electrolysis enables decarboxylative coupling of alkenyl acids with diazo compounds

Herein, we have reported an efficient and green paired electrolysis strategy for decarboxylative coupling of alkenyl acids with diazo compounds, providing a broad range of β,γ-alkenyl esters and amides.

Site-specific Umpolung amidation of carboxylic acids via triplet synergistic catalysis

Development of catalytic amide bond-forming methods is important because they could potentially address the existing limitations of classical methods using superstoichiometric activating reagents. In this paper, we disclose an Umpolung amidation reaction of carboxylic acids with nitroarenes and nitroalkanes enabled by the triplet synergistic catalysis of FeI2, P(V)/P(III) and photoredox catalysis, which avoids the production of byproducts from stoichiometric coupling reagents. A wide range of carboxylic acids, including aliphatic, aromatic and alkenyl acids participate smoothly in such reactions, generating structurally diverse amides in good yields (86 examples, up to 97% yield). This Umpolung amidation strategy opens a method to address challenging regioselectivity issues between nucleophilic functional groups, and complements the functional group compatibility of the classical amidation protocols. The synthetic robustness of the reaction is demonstrated by late-stage modification of complex molecules and gram-scale applications.

Metal‐Free Decarboxylation of α,β‐Unsaturated Carboxylic Acids for Carbon–Carbon and Carbon–Heteroatom Coupling Reactions

Metal‐free decarboxylative coupling reactions represent an alternative paradigm for carbon–carbon or carbon–heteroatom bond formation that complement more traditional metal catalysis approaches. In this review, recent advances in metal‐free decarboxylation reactions of α,β‐unsaturated carboxylic acids are highlighted. Two major reaction classes are covered: 1) generation of C–C, C–N, C–S, C–X bonds using propiolic acids; 2) transformations of alkenyl acids for C–C, C–P, C–N, C–S, C–X bond‐forming. Some cases involving electrochemistry and photochemistry represent a frontier area for carbon–carbon and carbon–heteroatom coupling processes. Additionally, the proposed mechanisms for both types of reactions are discussed.

Recent advances in decarboxylative C-C bond formation using direct or in situ generated alkenyl acids

ABSTRACTIn recent years, the reactions of abundantly available, inexpensive, and structurally diverse alkenyl acids (-C=C-COOH) with C-X (X = halogen) or C-H coupling partner have emerged as vital strategies for the streamlined synthesis of functionalized alkenes with extrusion of innocuous CO2. Various alkenyl acids such as cinnamic acids can act as stable surrogates for the polymerization prone styrenes/olefins, which otherwise need special attention for their handling and storage. Furthermore, cinnamic acids can be easily prepared through various methodologies including Knoevenagel-Doebner (KD) condensation, Heck coupling reaction, etc. Recently, various one-pot tandem methodologies involving the decarboxylative coupling of KD/Heck sequence with C-H or C-X substrate have come into fore. The present review article edifies about the recent advances, scope and limitations for C-C bond formation via (i) direct decarboxylative functionalization of C-X or C-H substrate with alkenyl acids, (ii) tandem one-pot multicomponent decarboxylative approaches (involving in situ generated alkenyl acids) e.g. coupling of KD/Heck sequences with C-X or C-H substrate.

Direct ortho‐Acyloxylation of Arenes and Alkenes by Cobalt Catalysis

AbstractAn efficient protocol for the cobalt‐catalyzed acyloxylation of arenes and alkenes with the assistance of an 8‐aminoquinolyl auxiliary group is reported. In this transformation, benzoic acids, alkenyl acids, and aliphatic acids could be readily involved to afford structurally diverse esters. It is worth noting that the silver sulfate (Ag2SO4) oxidant is renewable and the directing group could be removed and recycled. The strategy represents the first successful example of transition metal‐catalyzed acyloxylation of alkenyl carboxamides C(sp2)−H bonds with carboxylic acids.magnified image

Copper-Catalyzed Decarboxylative Coupling of Alkenyl Acids with P(O)H Compounds at Room Temperature

Copper-Catalyzed Decarboxylative Coupling of Alkenyl Acids with P(O)H Compounds at Room Temperature

Solvent‐Controlled Copper‐Catalyzed Radical Decarboxylative Coupling for Alkenyl C(sp2)−P Bond Formation

AbstractThe first solvent‐controlled copper‐catalyzed oxidative decarboxylative coupling of alkenyl acids with P(O)H compounds for alkenyl C(sp2)−P bond formation by a free‐radical process is reported. The reaction enables the highly chemo‐ and stereoselective synthesis of various (E)‐alkenylphosphonates and (E)‐alkenylphosphinate oxides in moderate to good yields. On the basis of this catalytic system, styrenes and β‐nitrostyrene as well as alkenyl acids can also give the corresponding products by cross‐dehydrogenative coupling and denitration, respectively. By altering the oxidant, the oxyphosphorylation of styrenes with P(O)H compounds readily yields β‐ketophosphonates. The reaction described here enables a versatile and practical avenue for the formation of valuable C−P bonds.

Acetonitrile-dependent oxyphosphorylation: A mild one-pot synthesis of β-ketophosphonates from alkenyl acids or alkenes

An efficient one-pot synthesis of β-ketophosphonates has been developed, via the reaction of α,β-alkenyl carboxylic acids or alkenes with H-phosphonates and air oxygen, catalyzed by CuSO4·5H2O in CH3CN. CH3CN plays a decisive role, probably by forming an active oxygen complex [(MeCN)nCuII-O-O·].

ChemInform Abstract: Regioselective Palladium‐Catalyzed Decarboxylative Cross‐Coupling Reaction of Alkenyl Acids with Coumarins: Synthesis of 3‐Styrylcoumarin Compounds.

AbstractA novel and efficient protocol for the regioselective synthesis of 3‐styrylcoumarins from readily available cinnamic acids and coumarins is presented.

ChemInform Abstract: Nickel‐Catalyzed Decarboxylative C—P Cross‐Coupling of Alkenyl Acids with P(O)H Compounds.

AbstractConditions A) are found to be optimal for the preparation of a large variety of phosphorus compounds bearing an (E)‐1‐alkenyl part.

Regioselective Palladium-Catalyzed Decarboxylative Cross-Coupling Reaction of Alkenyl Acids with Coumarins: Synthesis of 3-Styrylcoumarin Compounds

A novel and efficient protocol for the regioselective synthesis of 3-styrylcoumarins from readily available cinnamic acids and coumarins is presented. The reaction proceeds via a decarboxylative cross-coupling mediated by a catalytic amount of Pd(OAc)2, with Ag2CO3 as an oxidant, and with 1,10-phenanthroline as a ligand. A plausible reaction mechanism for this process is depicted, and the resulting 3-styrylcoumarins show excellent fluorescence quantum yields.

Nickel-catalyzed decarboxylative C-P cross-coupling of alkenyl acids with P(O)H compounds.

The first nickel-catalyzed decarboxylative C-P coupling of a wide range of alkenyl acids with various P(O)H compounds, especially for H-phosphonates, has been developed, affording a versatile and efficient tool for the preparation of valuable (E)-1-alkenylphosphonates, (E)-1-alkenylphosphinate oxides, and (E)-1-alkenylphosphine oxides with high stereoselectivity and broad substrate applicability. DFT calculation revealed that the phosphine ligand exhibits better catalytic performance than the nitrogen ligand in the reductive elimination step owing to the stronger nucleophilicity and larger size.

ChemInform Abstract: Regioselective Synthesis of Isocoumarins by Ruthenium‐Catalyzed Aerobic Oxidative Cyclization of Aromatic Acids with Alkynes

Abstract21 examples

Regioselective synthesis of isocoumarins by ruthenium-catalyzed aerobic oxidative cyclization of aromatic acids with alkynes

The highly regioselective aerobic oxidative cyclization of aromatic, heteroaromatic and alkenyl acids with alkynes in the presence of catalytic amounts of [{RuCl(2)(p-cymene)}(2)], AgSbF(6) and Cu(OAc)(2)·H(2)O providing isocoumarin derivatives was investigated.