Palladium Catalyzed C-O Bond Formation: Synthesis of Aryl Benzoates

A [Pd]-catalyzed intermolecular C-O bond formation strategy, is established towards the synthesis of aryl esters. Coupling of carboxylic acids with iodoarenes has been accomplished. Interestingly, water TBHP served as the reaction medium. This process found to be compatible with a good range of functional groups

Time and Temperature Dependent Palladium-Catalyzed Stereo- and Regioselective Alkoxy-arylation of Triple Bonds: Synthesis of (E)/(Z)1,1-Disubstituted-3-(1-Phenylalkylidene)-1,3-dihydroisobenzofurans

The development of synthetic strategies enabling the stereo- and regio-selective synthesis of organic molecules is indispensable in the pharmaceutical industry. This work describes a stereo- and regioselective synthesis of (E)/(Z)-1,1-disubstituted-3-(1-arylalkylidene)-1,3-dihydroisobenzofurans catalyzed by palladium. The DHIBFs are achieved from readily available aryl bromides and ortho-alkyne tertiary alcohols via intermolecular aryl Heck coupling and intramolecular oxo-cyclization of the suitably situated hydroxyl group. Significantly, it was demonstrated that a Z-isomer was formed as a substantial isomer at 80 °C for 6 h, whereas the stable E-isomer was the predominant one at slightly vigorous conditions (100 °C for 12 h). In addition, careful observation has also led to the realization that this double isomerization from Z- to E-isomer was triggered in the NMR tube itself in CDCl3 at room temperature. Significantly, this protocol, for the first time, enabled the synthesis of heavily substituted dihydroisobenzofurans, especially, bearing a tetra-substituted double bond

Facile enantiospecific syntheses of oxabicyclo4.4.0]decene-diones from carvone via mild Lewis acid mediated lactonizations

An efficient and concise enantiospecific syntheses of oxabicyclo4.4.0]decene-diones have been accomplished starting from carvone. This strategy is a chiron based approach by making use of mild Lewis acid mediated intramolecular lactonization as key step for the formation of fused bicyclic lactones. Notably, these bicyclic lactones constitute bicyclic carbon framework of diterpene natural products

Propargyl alcohols as alkyne sources: Synthesis of heterocyclic compounds under microwave irradiation

Fused heterocyclic compounds with alkyne substituent, have been achieved using a domino microwave-assisted [Pd]-catalysis. Interestingly, tert-propargyl alcohols underwent a selective degradative β-carbon cleavage and served as masked alkynyl equivalents, in water as the sole reaction medium. Dihydrobenzofurans, indolines, and oxindoles have been accomplished using this dual C–C bond-forming strategy

Additions and Corrections

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Time and Temperature Dependent Palladium-Catalyzed Stereo- and Regioselective Alkoxy-arylation of Triple Bonds: Synthesis of (E)/(Z)-1,1-Disubstituted-3-(1-Phenylalkylidene)-1,3-dihydroisobenzofurans

The development of synthetic strategies enabling the stereo- and regio-selective synthesis of organic molecules is indispensable in the pharmaceutical industry. This work describes a stereo- and regioselective synthesis of (E)/(Z)-1,1-disubstituted-3-(1-arylalkylidene)-1,3-dihydroisobenzofurans catalyzed by palladium. The DHIBFs are achieved from readily available aryl bromides and ortho-alkyne tertiary alcohols via intermolecular aryl Heck coupling and intramolecular oxo-cyclization of the suitably situated hydroxyl group. Significantly, it was demonstrated that a Z-isomer was formed as a substantial isomer at 80 °C for 6 h, whereas the stable E-isomer was the predominant one at slightly vigorous conditions (100 °C for 12 h). In addition, careful observation has also led to the realization that this double isomerization from Z- to E-isomer was triggered in the NMR tube itself in CDCl3 at room temperature. Significantly, this protocol, for the first time, enabled the synthesis of heavily substituted dihydroisobenzofurans, especially, bearing a tetra-substituted double bond

Transition-Metal Catalyzed Stereoselective γ-Arylation and Friedel-Crafts Alkylation: A Concise Synthesis of Indenes

A highly stereoselective [Pd]-catalyzed arylation of tert-alkenols, is presented and applied to the synthesis of indenes using intramolecular Friedel–Crafts alkylation sequence. The initial Heck reaction is performed by using water as the green solvent. A simple acid triggers intramolecular alkylation in short reaction times at room temperature. Notably, indenes have been accomplished using a single column chromatography technique

An enantiospecific total synthesis of (-)-patchouli alcohol

An enantiospecific total synthesis of patchouli alcohol, starting from the readily available monoterpene (R)-carvone, has been accomplished. A tandem double Michael reaction-alkylation sequence and single electron mediated 6-endo trig cyclisation reaction have been employed as key steps

Enantiospecific syntheses of oxacyclodecanes from carvone via mild Lewis acid mediated etherifcation

An efficient enantiospecific syntheses of oxatri-/tetra-cyclodecanes have been accomplished starting from (R)-carvone. A mild Lewis acid (BF3.OEt2) mediated intramolecular etherification is used as the key step. Structurally aesthetic tri- and tetracyclic ethers have been synthesized

An enantiospecific total synthesis of (−)-patchouli alcohol

An enantiospecific total synthesis of patchouli alcohol, starting from the readily available monoterpene (R)-carvone, has been accomplished. A tandem double Michael reaction-alkylation sequence and single electron mediated 6-endo trig cyclisation reaction have been employed as key steps