Synthesis Of Isocoumarins Research Articles

Super acid catalysed sequential hydrolysis/cycloisomerization of o-(acetylenic)benzamides under microwave condition: Synthesis, antinociceptive and antiinflammatory activity of substituted isocoumarins

Synthesis of isocoumarins and related compounds via triflic acid promoted hydrolysis/cyclization sequence of 2-(alkynyl)benzamides under microwave condition was achieved. The substrate scope of the reaction was broad to include not only aromatic but also polyaromatic and heteroaromatic motifs, thus highlighting the significance of this methodology. One-pot operation, short reaction time, good chemical yields and excellent regioselectivity are the advantages of this protocol. All the synthesized compounds were evaluated for their antinociceptive and antiinflammatory activities using in vivo rodent models.

Water as a green solvent for efficient synthesis of isocoumarins through microwave-accelerated and Rh/Cu-catalyzed C–H/O–H bond functionalization

Green chemistry that uses water as a solvent has recently received great attention in organic synthesis. Here we report an efficient synthesis of biologically important isocoumarins through direct cleavage of C–H/O–H bonds by microwave-accelerated and Rh/Cu-catalyzed oxidative annulation of various substituted benzoic acids, where water is used as the only solvent in the reactions. The remarkable features of this “green” methodology include high product yields, wide tolerance of various functional groups as substrates, and excellent region-/site-specificities, thus rendering this methodology a highly versatile and eco-friendly alternative to the existing methods for synthesizing isocoumarins and other biologically important derivatives such as isoquinolones.

Palladium-Catalyzed Synthesis of Isocoumarins and Phthalides via tert-Butyl Isocyanide Insertion

A novel and highly efficient strategy for the synthesis of isocoumarins and phthalides through a palladium(0)-catalyzed reaction incorporating tert-butyl isocyanide has been developed. This process, providing one of the simplest methods for the synthesis of this class of valuable lactones, involves two steps including cyclization reaction and simple acid hydrolysis. The methodology is tolerant of a wide range of substrates and applicable to library synthesis.

ChemInform Abstract: Versatile Synthesis of Isocoumarins and α‐Pyrones by Ruthenium‐Catalyzed Oxidative C—H/O—H Bond Cleavages.

AbstractAryl‐substituted alkynes and electron‐rich carboxylic acids are preferentially converted.

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

Abstract21 examples

Ru-Catalyzed Synthesis of Isocoumarins from Benzoic Acids and Alkynes

Key words isocoumarins - benzoic acids - alkynes - ruthenium catalysis

Versatile Synthesis of Isocoumarins and α-Pyrones by Ruthenium-Catalyzed Oxidative C–H/O–H Bond Cleavages

An inexpensive cationic ruthenium(II) catalyst enabled the expedient synthesis of isocoumarins through oxidative annulations of alkynes by benzoic acids. This C-H/O-H bond functionalization process also proved applicable to the preparation of α-pyrones and was shown to proceed by rate-limiting C-H bond ruthenation.

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.

Isocoumarin and Its Derivatives: An Overview on their Synthesis and Applications

The prevalence of isocoumarins in numerous natural products that exhibit a wide range of biological activities has generated a continued and enormous interest among synthetic and medicinal chemists. The isocoumarin framework represents one of the privileged structures for the development of natural product-inspired compounds of potential biological interest. Considerable efforts have been de- voted towards the synthesis of isocoumarins via either traditional or transition-metal catalyzed reactions. Among the metal catalyzed re- actions, the use of Cu, Pd, Ag, Ru, Rh or Ir salts/complexes for the construction of isocoumarin ring are noteworthy. Among the other methodologies, halo-lactonization emerged as a practical process. Apart from preparing a variety of isocoumarins and thienopyranones, synthesis of naturally occurring and bioactive isocoumarins have been carried out by using cutting edge technologies. This review article will briefly cover all these aspects along with the synthetic utility of isocoumarins, highlighting recent developments.

ChemInform Abstract: Diselenide‐ and Disulfide‐Mediated Synthesis of Isocoumarins.

AbstractA diselenide‐ or disulfide‐catalyzed approach to the synthesis of isocoumarins is developed by employing hypervalent iodine reagents under very mild reaction conditions.

Syntheses of 3-substituted 3,4-dihydroisochromen-1-ones

isochromen-1-one, montmorillonite K-10. The isochromen-1-one skeleton is found in a variety of natural products [1]. Isocoumarins and their derivatives, such as dihydroisocoumarins, are secondary metabolites of a wide variety of microbial, plant, and insect sources and are used in the synthesis of other medicinal compounds [2-4]. Most methods available for the construction of 3-substituted 3,4-dihydroisochromen-1-one nucleus suffer from one or more drawbacks, such as the multistep procedure [5] and use of expensive and hazardous reagents and solvents. Many studies on isocoumarin synthesis, including cyclization of keto acids and electrophilic cyclization of alkynylbenzoic acid derivatives, have been reported [6, 7]. Finding an efficient method for the synthesis of 3,4-dihydroisochromen-1-one is still a challenge.

ChemInform Abstract: Palladium-Catalyzed Synthesis of Isocoumarin and 1-Isoquinolinone Derivatives.

In the presence of copper(I) chloride, the palladium catalyzed oxidation of methyl 2-ethenylbenzoates and 2-ethenylbenzamides have been studied. This reaction was used to form isocoumarins and 1-isoquinolinones.

ChemInform Abstract: Synthesis of Isocoumarins and α-Pyrones via Palladium-Catalyzed Annulation of Internal Alkynes.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Total Synthesis of Coriandrin and 7-Demethylcoriandrin via a New Synthesis of Isocoumarins.

Abstract Indenone epoxides 8 , prepared from the corresponding indenones, have been shown to undergo clean thermal rearrangement to give isocoumarins 10 in high yields. This synthesis of isocoumarins, when applied to oxaindacenone 7 , resulted in the total synthesis of coriandrin ( 1 ).

Diselenide‐ and Disulfide‐Mediated Synthesis of Isocoumarins

AbstractCyclizations of stilbenecarboxylic acids to the corresponding isocoumarin derivatives using diselenide or disulfide reagents have been developed. By employing bis(triflouroacetoxy)iodobenzene as oxidant for the 6‐endo‐trig cyclizations a variety of dihydroisocoumarins have been prepared in good yields. This method is capable of forming isocoumarins and dihydroisocoumarin derivatives by a cyclization–elimination route.

ChemInform Abstract: Palladium‐Catalyzed Aryl Halide Carbonylation—Intramolecular O‐Enolate Acylation: Efficient Isocoumarin Synthesis, Including the Synthesis of Thunberginol A.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An efficient synthesis of isocoumarins via a CuI catalyzed cascade reaction process

3-Alkyl isocoumarins are provided by CuI/amino acid-catalyzed Sonogashira coupling reaction of o-bromo benzoic acids and terminal alkynes and the subsequent additive cyclization. This cascade process allows synthesis of diverse isocoumarins by varying both coupling partners bearing a wide range of functional groups.

Solid-Phase Synthesis of Isocoumarins: A Traceless Halocyclization Approach

A straightforward and traceless solid-phase methodology was developed for the synthesis of isocoumarins. This two-step process involves a Sonogashira cross-coupling reaction between polymer-bound 2-bromobenzoates and terminal alkynes, followed by an electrophile-induced halocyclization of the resulting 2-(alk-1-ynyl)benzoates through activation of the triple bond with the subsequent release of the 3-substituted 4-haloisocoumarins. This polymer-bound parallel synthetic approach allowed us to achieve large diversity in good to excellent yields and purities.

Palladium-catalyzed aryl halide carbonylation–intramolecular O-enolate acylation: efficient isocoumarin synthesis, including the synthesis of thunberginol A

Exposure of a series of ?-(o-haloaryl)-substituted ketones to palladium-catalyzed carbonylation conditions leads to the formation of the corresponding isocoumarins. Balloon pressure of CO is sufficient to achieve high yielding reactions, and both cyclic and acyclic ketones are efficient substrates. The utility of the method is illustrated by a short synthesis of the natural product thunberginol A.

Synthesis of Isocoumarin via PTSA-Catalyzed Annulation of Diarylalkynes

p-Toluenesulfonic acid (PTSA) in ethanol was used as a mild acid catalyst for the annulation of various functionalized diarylalkynes under microwave irradiation. This metal-free process allowed the synthesis of a range of 3-aryl-substituted isocoumarins in good yields.