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The total synthesis of physarorubinic acid, a polyenoyltetramic acid plasmoidal pigment from Physarum polycephalum, is described in a series of steps from (E)-3-iodoacrylic acid 6 and employs aminolysis of the pentaene thioester 11 as a key synthetic step. Lacey-Dieckmann cyclisation and subsequent deprotection then affords physarorubinic acid 1 in high yield and purity.

We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes. This mild and operationally simple protocol is distinguished by its broad substra

Introduction: Novel radiotracer development for imaging dopamine transporters is a subject of interest because although [99mTc]TRODAT-1, [123I]β-CIT, and [123I]FP-CIT are commercially available;99Mo/99mTc generator is in short supply and123I production is highly dependent on compact cyclotron. Therefore, we designed a novel positron emission tomography (PET) tracer based on a tropane derivative through C-2 modification to conjugate NOTA for chelating68Ga, a radioisotope derived from a68Ge/68Ga generator. Methods: IPCAT-NOTA 22 was synthesized and labeled with [68Ga]GaCl4 ? at room tem-perature. Biological studies on serum stability, LogP, and in vitro autoradiography (binding assay and competitive assay) were performed. Furthermore, ex vivo autoradiography, biodis-tribution, and dynamic PET imaging studies were performed in Sprague Dawley rats. Results: [68Ga]IPCAT-NOTA 24 obtained had a radiochemical yield of ≥90% and a specific activity of 4.25 MBq/nmol. [68Ga]IPCAT-NOTA 24 of 85% radiochemical purity (RCP%) was stable at 37°C for up to 60 minutes in serum with a lipophilicity of 0.88. The specific binding ratio (SBR%) reached 15.8 ± 6.7 at 60 minutes, and the 85% specific uptake could be blocked through co-injection at 100-and 1000-fold of the cold precursor in in vitro binding studies. Tissue regional distribution studies in rats with [68Ga]IPCAT-NOTA 24 showed striatal uptake (0.02% at 5 minutes and 0.007% at 60 minutes) with SBR% of 6%, 25%, and 62% at 5–15, 30–40, and 60–70 minutes, respectively, in NanoPET studies. The RCP% of [68Ga]IPCAT-NOTA 24 at 30 minutes in vivo remained 67.65%. Conclusion: Data described here provide new information on the design of PET probe of conjugate/pendent approach for DAT imaging. Another chelator or another direct method of intracranial injection must be used to prove the relation between [68Ga]IPCAT-NOTA 24 uptake and transporter localization.

Two truncated analogues of the polyenyl photoprotective xanthomonadin pigments have been synthesised utilising an iterative Heck-Mizoroki (HM)/iododeboronation cross coupling approach and investigated as models of the natural product photoprotective agent

Approaches to the polyene natural product xanthomonadin, an octaenyl electron-deficient bacterial photoprotective agent, and its debromo analogue, were developed. These involved the iterative cross-coupling of multiple C2-fragments, using a vinylboronate

A method is reported for palladium-catalyzed N-quinolyl carboxamide-directed olefination of the unactivated C(sp3)-H bonds of phthaloyl alanine with a broad range of vinyl iodides at room temperature. This reaction represents the first example of the stereoretentive installation of multisubstituted terminal and internal olefins onto unactivated C(sp3)-H bonds. These methods enable access to a wide range of challenging β-vinyl α-amino acid products in a streamlined and controllable fashion, beginning from simple precursors.

Previously, we reported a click-chemistry based approach to the synthesis of a novel class of histone deacetylase (HDAC) inhibitors [1]. The lead compound NSC746457 was found to be as potent as SAHA (Vorinostat). Further optimization of NSC746457 by using

Disclosed herein are substituted allylamines having structural Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and the methods of their use thereof. (I)

Histone deacetylase inhibitors (HDACi) are a relatively new class of chemotherapy agents. Herein, we report a click-chemistry based approach to the synthesis of HDACi. Fourteen agents were synthesized from the combination of two alkyne and seven azido pre

Mechanistic studies of the Heck-Mizoroki reaction of a vinylboronate ester with electronically different (four-substituted) aryl iodides shows that electron donors accelerate the cross-coupling, demonstrating that the oxidative addition step is not rate d

Stereoselective construction of conjugated trienoic acids was achieved through two successive Stille reactions, the first step consisting of the coupling of (E)-1,2-bis(tributylstannyl)ethene and tributylstannyl (Z)- or (E)-3-iodoalk-2-enoates. Two different routes were used for the second step: (1) cross-coupling of the stannyldienoic acid reagents and vinyl iodides, or (2) cross-coupling of vinylstannane reagents and the tributylstannyl 5-iodopenta-2,4-dienoates generated by iododestannylation of stannyldienes. Vinylstannanes synthesized by stannylmetalation of the Negishi dienyne derived from β- or α-ionone and safranal thus provided access to stereodefined retinoic acids. Some retinoid and yne analogues were also prepared by Sonogashira coupling. Georg Thieme Verlag Stuttgart.

The crystal structures of cis-3-iodoacrylic acid (1), trans-3-iodoacrylic acid (2), trans-3-iodoacrylic acid methyl ester (3), 3,3-diiodopropanoic acid (4), and trans-2,3-diiodoacrylic acid (5) are reported. Compounds 1 and 2 are the kinetic and thermodynamic products, respectively, of the hydroiodination of propiolic acid. Compound 4 results from addition of a second equivalent of hydroiodic acid to 1 or 2, whereas 5 results from the addition of trace elemental iodine to propiolic acid. Copyright Taylor & Francis Group, LLC.

Readily available difluoroenol iodides and stannanes undergo palladium-catalysed coupling reactions with alkenylstannanes and iodides, respectively, to afford a trial set of difluorinated 1,3- and 1,4-dienes, which were then exposed to AD conditions. A nu

[reaction: see text] A new route, of potential strategic importance, to a difluorosugar analogue has been developed. Key steps included a Stille coupling and a highly regio- and enantioselective dihydroxylation of a highly substituted diene. Protecting gr

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(equation presented) Elaiolide (2) The 16-membered macrodiolide elaiolide (2) has been prepared in 20 steps from the ketone (S)-8 in 9.3% overall yield with a diastereoselectivity of 76%. Key steps included the copper(l) thiophene-2-carboxylate promoted c

Z-3-iodoacrylic acid Z-1, that formed by reacting propiolic acid 2 with 57% aqueous III at 80-85 °C, was efficiently converted into the isomeric acid E-1 by treatment in the same conditions.

The series of furyl enone esters, 4a-c, were synthesized from furan or furfural by straightforward routes. Their thermal intramolecular Diels-Alder reactions to give the tricyclic ketones 5a-c were studied in acetonitrile and toluene at two temperatures and the kinetics of the reactions determined. A comparison of these data with that obtained for the corresponding esters 2 to give the lactones 3 indicates that the rate enhancements seen for the esters (rate of dimethyl 310 times that of monomethyl) are much larger than those seen for the ketones (rate of dimethyl 6.8 times that of monomethyl). Thus, this is additional evidence for the earlier hypothesis that the presence of the oxygen atom in the tether is a factor responsible for the larger than normal rate enhancements.

An efficient synthesis of dienamides of insecticidal interest has been stereoselectively achieved featuring a Stille cross-coupling reaction as the key step.

The stereoselective synthesis of vinylstannanes bearing carboxylic acid function was achieved from acetytenic acids via stannylcupration reaction. In homoallylic series, regioselectivities are highly dependant on the nature of stannylanionids and on the p

The 16-membered macrodiolide 4, corresponding to the macrocyclic core of elaiophylin (1), was prepared via the copper-mediated cyclodimerisation of stannane 3.

(E)- or (Z)-Enynoic acids and (2E,4E)- or (2Z,4E)-dienoic acids can be obtained in good yields under mild conditions through palladium-catalysed cross coupling of (E)- or (2)-3-iodoprop-2-enoic acid with alkynylzinc or vinyltin reagents.

cis N-Alkyl-β-halogenoacrylamides have an s-skew conformation which is solvent dependent.The more polar the solvent the smaller is the amount of skew in the conformation.The skew angle is also halogen dependent.