1119-67-1

Reaction of terminal acetylenes with bis(sym-collidine)iodine(I) hexafluorophosphate in methylene chloride leads in good yields to the formation of iodoacetylenes.

Iodoethynylbenzene as iodoalkyne model compound was aminocarbonylated with tert-butylamine under carbon monoxide atmosphere in the presence of in situ palladium(0) catalysts. The formation of the unsaturated carboxamide (alkynyl amide) is always accompanied by that of the Glaser coupling product, diphenylbutadiyne. The yield of the amide-forming reaction was optimised by the systematic variation of the phosphine ligand, carbon monoxide pressure and temperature. The scope of the reaction was investigated by using various primary and secondary amines including amino acid methyl esters as N-nucleophiles. 17α-(Iodoethynyl)-testosterone was also functionalised by using this methodology providing the corresponding 17α-(carboxamidoethynyl)-testosterone derivatives in up to 96% yields. The reaction was extended to 1-(iodoethynyl)cyclohex-1-ene and 1-iodohex-1-yne. Ethyl iodopropiolate gave the enamine type product by the addition of amine to the alkyne functionality which was formed from the iodoalkyne via deiodination under standard aminocarbonylation conditions. The bromo analogue, bromoethynylbenzene has shown lower reactivity than the corresponding iodo derivative.

A palladium-catalyzed iodoalkynation of norbornene has been realized with the use of alkynyl iodides 1, which is found to be strongly solventdependent. MeCN favors 1,7-iodoalkylation product 3 while CCl4 leads to 1,2-iodoalkylation product 4.

The 13C NMR spectra of two different iodoalkynes, 1-iodo-1-hexyne (1) and diiodoethyne (2), exhibit a strong solvent dependence. Comparisons of the data with several common empirical models, including Gutmann's Donor numbers, Reichardt's ENT, and Taft and Kamlet's β and π*, demonstrate that this solvent effect arises from a specific acid-base interaction. Solvent basicity measures such as Donor numbers and β values correlate well with the α-carbon chemical shift of 1, but polarity measures such as ENT and π* do not correlate. The similarity of the solvent effect for 1 and 2 suggests that carbon-carbon bond polarization may not play a role in the change in chemical shift, as previously hypothesized.

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Treatment of terminal alkynes with (diacetoxyiodo)benzene, potassium iodide, and copper(I) iodide afforded 1-iodoalkynes in good to excellent yields under mild conditions. Georg Thieme Verlag Stuttgart.

A general method for the synthesis of pure samples of unsymmetrically disubstituted diacetylenes of the type CH3-(CH2)(n)-C=C=C=C-CH2-OH (n=2,3,4,5) is described in detail. The materials could be polymerized thermally, in the liquid state.

A convenient approach to assemble 1,2,3-triazole-fused 4 H -3,1-benzoxazines has been developed. Diverse alcohol-tethered 5-iodotriazoles, readily accessible by a modified protocol of Cu-catalyzed (3+2)-cycloaddition, were utilized as precursors of the target fused heterocycles. The intramolecular C-O coupling proceeded efficiently under base-mediated transition-metal-free conditions, furnishing cyclization products in yields up to 96%. Suppression of the competing reductive cleavage of the C-I bond was achieved by the use of Na 2CO 3in acetonitrile at 100 °C. This practical and cost-effective procedure features a broad substrate scope and valuable functional group tolerance.

The present disclosure provides, inter alia, a compound having the structure (1). Also provided are compositions containing a pharmaceutically acceptable carrier and one or more compounds according to the present disclosure. Further provided are methods f

We describe here for the first time the synthesis of isochromenones fused to selenophenes. 5H-Selenopheno[3,2-c]isochromen-5-ones were obtained through a double intramolecular cyclization of methyl 2-(organyl-1,3-diynyl)benzoate promoted by electrophilic species of selenium generated in situ by the reaction of dialkyl diselenides with Oxone, using ethanol as solvent. The reactions were conducted satisfactorily under mild conditions, using a range of 1,3-diynes and dialkyl diselenides as substrates. A total of sixteen unprecedent 5H-selenopheno[3,2-c]isochromen-5-ones were selectively obtained in moderate to good yields (40–86%) under reflux in an open flask and in short reaction times (1.0–2.5 h). (Figure presented.).

Base-mediated cyclization of (5-iodo-1,2,3-triazolyl)phenols was proposed as a new synthetic strategy for the in situ generation of diazoimines via electrocyclic ring opening of the fused heterocycle. Cu-catalyzed amination of the intermediate diazoalkanes was employed to develop an efficient cascade approach to functionalized benzoxazoles.

A diverse range of Lewis acidic alkyl, vinyl and aryl boranes and borenium compounds that are capable of new carbon–carbon bond formation through selective migratory group transfer have been synthesised. Utilising a series of heteroleptic boranes [PhB(Cs

Two complementary catalytic systems are reported for the 1,3-dipolar cycloaddition of azides and iodoalkynes. These are based on two commercially available/readily available copper complexes, [CuCl(IPr)] or [CuI(PPh 3)3], which are active at low metal loadings (PPh 3 system) or in the absence of any other additive (IPr system). These systems were used for the first reported mechanistic studies on this particular reaction. An experimental/computational-DFT approach allowed to establish that (1) some iodoalkynes might be prone to dehalogenation under copper catalysis conditions and, more importantly, (2) two distinct mechanistic pathways are likely to be competitive with these catalysts, either through a copper(III) metallacycle or via direct-activation of the starting iodoalkyne.

Hexamethylene bis(N-methylimidazolium) bis(dichloroiodate) (HMBMIBDCI), an ionic liquid iodinating reagent, have been prepared and characterized. Its ability to perform iodination reactions with a variety of substrates has been explored. In general, iodination reactions of aromatic and heteroaromatic amines proceed with good yields in the absence of solvent. Reactions of terminal alkynes in the presence of 1,8-diazabicyclo [5.4.O] undec-7-ene and tetrahydrofuran have been investigated as well.

The present application provides methods and catalysts for activation of carboxylic acids for organic reactions. In particular, methods are disclosed for direct nucleophilic addition reactions, such as, amidation reactions with amines, cycloadditions, and conjugate additions, using boronic acid catalysts of formula I, II or III: Also included are novel boronic acid catalysts of formula IV, V and III:

A convenient approach toward polycyclic frameworks containing fused 1,2,3-triazoles is described. The synthesis consists of a Cu-catalyzed cycloaddition and an intramolecular Pd-catalyzed direct arylation or Heck reaction, and affords the products in good to excellent yields.

In the presence of a cationic gold(I) catalyst and N-halosuccinimide, both trimethylsilyl-protected and terminal alkynes are converted into alkynyl halides. Further experiments showed that silyl-protected alkynes undergo electrophilic iodination and bromination under Bronsted acid catalysis, whilst terminal alkynes require a cationic gold catalyst. The former reactions probably proceed via activation of the electrophile, whilst the latter reactions proceed via a gold(I) acetylide intermediate. Gold-catalysed halogenation was further combined with gold-catalysed hydration and subsequent annulation to provide convenient routes to iodomethyl ketones and five-membered aromatic heterocycles. Copyright

The first example of Cr-catalyzed asymmetric alkynylation of aldehydes with 1-iodo- and 1-bromoalkynes was developed. The use of tethered bis(8-quinolinato) chromium catalyst (3 mol %) allowed preparation of enantioenriched propargyl alcohols with good yields and enantioselectivities up to 92% ee. 1-Bromoalkynes can be activated by the introduction of a cobalt porphine cocatalyst, which enables shorter reaction times without any loss of enantiocontrol.

Clathculins A and B represent a new class of vic-diamine alkaloids containing a PA2 unit as the basic structure. We report the first total syntheses of 1 and 2, which confirm the assigned structure of each. Dependence of their NMR spectroscopic behavior a

(Figure presented) The thermally promoted cycloaddition between alkynyliodides and nitrile oxides is reported. The process offers excellent regioselectivity and a broad scope with respect to both the iodoalkynes and chloro-oximes. Further functionalization of the highly decorated iodoisoxazole motifs can be achieved via Suzuki cross-coupling.

A series of novel polyacetylene substituted 2-hydroxy acids and derivatives were prepared and characterized. Alkylation of butane-2,3-diacetal (BDA) protected glycolic acid with iodoalkyl substituted polyacetylene compounds gave the corresponding diacetal protected polyacetylene substituted 2-hydroxy acids. Diacetal deprotection through acid mediated hydrolysis, transesterification or aminolysis afforded the 2-hydroxy-polyacetylenic acid, ester or amide derivatives. Twenty one of these novel compounds were tested against 10 microbes of clinical importance and several of them showed good antimicrobial activity, in particular against Pseudomonas aeruginosa.

The present invention relates to a class of conjugated unsaturated compounds, to a method of preparing such compounds, and to the polymerisation and bio-active uses of such compounds including their use as antimicrobial agents. The invention particularly relates to compounds containing three conjugated unsaturated moieties, at least two of which are yne moieties.

A modular synthesis of unsaturated 1-monoacylglycerols (1) from cis-1-iodo-1-alkenes [cis-RCH=CHI] and unsaturated carboxylic acids [CH 2=CH(CH2)nCO2H] is described. The method revolves around a Suzuki coupling to establish olefin geometry.

Cross-linkable, phosphonate containing supramoleuclar aggregates are disclosed, which may be used to advantage, for example, as drug delivery vehicles for the treatment of bone-related disorders.

matrix presented Four linear polyacetylenic compounds were synthesized. Pentadeca-6,8,10-triynoic acid 1 and octadeca-8,10,12-triynoic acid 2 were synthesized by using acetylene coupling reactions. The syntheses of (Z)-hexadec-11-en-7,9-diynoic acid 3 and (Z)-octadec-12-en-7,9-diynoic acid 4 by using vinylic telluride coupling reactions were accomplished.

Highly stable, enantiomerically pure cyclopropylboronic esters are desirable building blocks for the preparation of a plethora of different cyclopropane derivatives. Whereas trans-configured compounds proved to be readily available, we herein report the f

Electrochemical oxidation of terminal acetylenes using a divided cell in the presence of NaI as a supporting electrolyte in MeOH brought about the efficient formation of the corresponding 1 -iodoacetylenes. On the other hand, use of LiCl instead of NaI un

Studies on the sp-sp intermolecular coupling reactions with the palladium water-soluble catalyst prepared in situ from palladium(II) acetate and sulfonated triphenylphosphine P(C6H4-m-SO3Na)3 (TPPTS) in a homogeneous acetonitrile-water system, without Cu(I) promotor, afford diynes with moderate yields (45-65percent).Under the same conditions, the sp2-sp coupling of 2-iodophenols or 2-iodoanilines and terminal alkynes followed by intramolecular cyclization gives indolic and furanic products in good yields (60-99percent).Under these aqueous conditions, an efficient and short synthesis of eutypine illustrated the synthetic potentiality of the coupling.Furthermore, through a series of kinetic and 31P NMR experiments, we have demonstrated that a mixture of Pd(OAc)2 and TPPTS affords spontaneously a palladium(0) complex, through formation of bivalent complex Pd(OAc)2(TPPTS)2.A detailed mechanism of the reaction has been investigated thoroughly and the pertinent rate constants measured.The resulting palladium(0) complex reacts with phenyl iodide via an oxidative addition.This complex is considerably less reactive than the corresponding complex generated from PPh3, probably due to steric effects.

It is shown that the methyl group cannot be used as a cheap, non-migrating group in the reactions of alkynyltrialkylborates with electrophiles.However, trimethylborane can be used as a methylboronating agent for alkynes, given the right choice of solvent, and this may be of use in terpene synthesis.

A simple and general one-pot procedure for the synthesis of 1-iodoalkynes is described based on the reaction of terminal acetylenes with bis(pyridine)iodine(I) tetrafluoroborate in the presence of sodium methoxide.The method now reported is superior to the literature procedures in scope, handling, and often yield.

The transfer reaction induced by iodination of lithium alkynyl "ate" complexes of organoboranes represents a novel route to unsymmetrical alkynes.Several potential "blocking" groups were examined in order to achieve the selective migration of one primary alkyl group and thereby increase the efficiency of this process.Best results were obtained with the combined use of the thexyl and methoxy moieties as "blocking" groups in this reaction.The required thexylalkylborinate intermediates were conveniently prepared in high yield from thexylchloroborane via hydroboration and methanolysis.Subsequent complexation with an appropriate lithium alkyne, followed by iodination, produced the desired unsymmetrical alkyne in high yield.Minimum amounts of the product resulting from competitive migration of the thexyl group were observed.Under these conditions, an efficient utilization of a primary alkyl group in this transfer reaction is achieved.Furthermore, the high tolerance of thexylchloroborane toward many functional groups and its high regioselectivity in terminal alkene hydroboration produces intermediates that are particularly useful for the synthesis of insect pheromones and not readily accessible via conventional organometallic procedures.

Benzoic acid and substituted benzoic acids are readily thallated by thallium(III) trifluoroacetate and subsequently reacted with palladium chloride and simple olefins, allylic halides, vinyl halides, or vinyl esters to give isocoumarins.The organic halide reactions are catalytic in palladium. 1,2- and 1,3-dienes also react catalytically to afford 4-alkylidene- and 3-vinyl-3,4-dihydroisocoumarins, respectively.Vinylcyclopropanes also afford 3-vinyl-3,4-dihydroisocoumarins.This highly convenient thallation-olefination approach appears quite general for the synthesis of isocoumarins.

Terminal alkynes 1-hexyne (1), tert-butylacetylene (2), and phenylacetylene (3) react with iodine in methanol to give only 1,2-diiodoalkenes.If the reactions are carried out in the presence of silver nitrate, however, diiodo ketones (RC(O)CHI2) and substi

1-Bromo- and 1-iodo-1-alkynes are alkylated by organocopper(I) compounds.Alkenylcopper(I) derivatives undergo substitution with retention of configuration leading to conjugated and functional enynes, from which conjugated dienes can be obtained.