33577-96-7

Upstream product

• 610-94-6 2-bromobenzoic acid methyl ester 
• 115-19-5 2-methyl-but-3-yn-2-ol 
• 610-97-9 o-iodo-methyl-benzoic acid 
• 88-67-5 2-Iodobenzoic acid 

Downstream Products

• 142458-58-0 2-(2-hydroxy-2-methyl-3-butyn-4-yl)-α-diazoacetophenone 
• 33577-99-0 2-ethynyl-benzoic acid methyl ester 
• 142458-81-9 methyl 2-(2-methoxy-2-methyl-3-butyn-4-yl)benzoate 
• 130818-20-1 2-(2-(4-methoxyphenyl)ethynyl)benzoic acid methyl ester 

Relevant academic research and scientific papers

Mechanistic Divergence in the Hydrogenative Synthesis of Furans and Butenolides: Ruthenium Carbenes Formed by gem-Hydrogenation or through Carbophilic Activation of Alkynes

Enynes with a tethered carbonyl substituent are converted into substituted furan derivatives upon hydrogenation using [Cp*RuCl]4 as the catalyst. Paradoxically, this transformation can occur along two distinct pathways, each of which proceeds via discrete pianostool ruthenium carbenes. In the first case, hydrogenation and carbene formation are synchronized (“gem-hydrogenation”), whereas the second pathway comprises carbene formation by carbophilic activation of the triple bond, followed by hydrogenative catalyst recycling. Representative carbene intermediates of either route were characterized by X-ray crystallography; the structural data prove that the attack of the carbonyl group on the electrophilic carbene center follows a Bürgi–Dunitz trajectory.

Silver triflate/: P -TSA co-catalysed synthesis of 3-substituted isocoumarins from 2-alkynylbenzoates

In this paper, we describe the silver triflate/p-toluenesulfonic acid co-catalysed synthesis of seventeen isocoumarins and two thieno[2,3-c]pyran-7-ones starting from 2-alkynylbenzoates and 3-alkynylthiophene-2-carboxylates, respectively. The reaction proceeds with absolute regioselectivity under mild reaction conditions and low catalyst loading, to afford the desired products in good to excellent yields. A conceivable reaction mechanism is proposed and supported by isotope-exchange tests, 1H NMR studies and ad hoc experiments.

Photophysical and theoretical studies of diphenylacetylene derivatives with restricted rotation

Diphenylacetylene derivatives containing electron-donor (amino) and electron-acceptor (ester) groups in 2,2′ or 3,2′ positions in phenyl rings were synthesized to study the effects of intramolecular charge transfer and stiffening of the conformation by in

Allenylphosphine oxides as simple scaffolds for phosphinoylindoles and phosphinoylisocoumarins

A range of phosphinoylindoles was prepared in one-pot from functionalized propargyl alcohols and a suitable P(III) precursor via a base-mediated reaction. The reaction proceeds via the intermediacy of allenylphosphine oxides. Similarly, phosphinoylisocoumarins were prepared from allenylphosphine oxides in a trifluoroacetic acid-mediated reaction; the latter also acts as a solvent. Interestingly, in the presence of wet trifluoroacetic acid, in addition to phosphinoylisocoumarins, phosphorus-free isocoumarins were also obtained. Key products were characterized by single crystal X-ray crystallography.

Base-catalyzed heterocyclization of 2-(R-ethynyl)benzohydroxamic acids

Sonogashira alkynylation of methyl 2-iodobenzoate with terminal acetylenes gave a series of methyl 2-(alk-1-yn-1-yl)benzoates which reacted with hydroxylamine in boiling methanol to produce five- or six-membered N-hydroxy lactams, 3-R-methylidene-2-hydroxy-2,3-dihydroisoindol-1-ones or 3-R-isoquinolin-1(2H)-ones, depending on the acetylenic substituent nature.

K3PO4-KOH mixture as efficient reagent for the deprotection of 4-aryl-2-methyl-3-butyn-2-ols to terminal acetylenes

A mixture of potassium hydroxide and potassium phosphate was found to be an active reagent mixture for the cleavage of 2-hydroxypropyl-protected acetylenes. The reaction was performed in toluene at reflux temperature and gave terminal acetylenes in good to excellent yields within very short periods of time. Numerous other functional groups are tolerated. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for full experimental and spectral details.

Base-catalyzed intramolecular heterocyclization of o-alkynylbenzhydrazides

The reaction of methyl o-(2-R-ethynyl)benzoates with hydrazine affords either fused 4-R-methylphthalazin-1-ones or 2-amino-3-R-methylideneisoindolin-1- ones. The latter are on treatment with KOH undergo recyclization into the corresponding 4-R-methylphthalazin- 1-ones.

New 2,4-Diamino-5-(2′,5′-substituted benzyl)pyrimidines as Potential Drugs against Opportunistic Infections of AIDS and Other Immune Disorders. Synthesis and Species-Dependent Antifolate Activity

In a continuing effort to design small-molecule inhibitors of dihydrofolate reductase (DHFR) that combine the enzyme-binding selectivity of 2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl)-pyrimidine (trimethoprim, TMP) with the potency of 2,4-diamino-5-methyl-6-(2′ ,5′-dimethoxybenzyl)pyrido[2,3-d]pyrimidine (piritrexim, PTX), seven previously undescribed 2,4-diamino-5-[2′-methoxy-5′-(substituted benzyl)]pyrimidines were synthesized in which the substituent at the 5′-position was a carboxyphenyl group linked to the benzyl moiety by a bridge of two or four atoms in length. The new analogues were all obtained from 2,4-diamino-5-(5′-iodo-2′-methoxybenzyl)pyrimidine via a Sonogashira reaction, followed, where appropriate, by catalytic hydrogenation. The new analogues were tested as inhibitors of DHFR from Pneumocystis carinii (Pc), Toxoplasma gondii (Tg), and Mycobacterium avium (Ma), three life-threatening pathogens often found in AIDS patients and individuals whose immune system is impaired as a result of treatment with immunosuppressive chemotherapy or radiation. The selectivity index (SI) of each compound was obtained by dividing its 50% inhibitory concentration (IC50) against Pc, Tg, or Ma DHFR by its IC50 against rat DHFR. 2,4-Diamino-[2′-methoxy-5′-(3-carboxyphenyl)-ethynylbenzyl] pyrimidine (28), with an IC50 of 23 nM and an SI of 28 in the Pc DHFR assay, had about the same potency as PTX and was 520 times more potent than TMP. As an inhibitor of Tg DHFR, 28 had an IC50 of 5.5 nM (510-fold lower than that of TMP and similar to that of PTX) and an SI value of 120 (2-fold better than TMP and vastly superior to PTX). Against Ma DHFR, 28 had IC50 and SI values of 1.5 nM and 430, respectively, compared with 300 nM and 610 for TMP. Although it had 2.5-fold lower potency than 28 against Ma DHFR (IC50 = 3.7 nM) and was substantially weaker against Pc and Tg DHFR, 2,4-diamino-[2′-methoxy-5′ -(4-carboxyphenyl)ethynylbenzyl]pyrimidine (29), with the carboxy group at the para rather than the meta position, displayed 2200-fold selectivity against the Ma enzyme and was the most selective 2,4-diamino-5-(5′-substituted benzyl)pyrimidine inhibitor of this enzyme we have encountered to date. Additional bioassay data for these compounds are also reported.

Rhodium Carbenoid Mediated Cyclizations of o-Alkynyl-Substituted α-Diazoacetophenones

o-Alkynyl-substituted α-diazoacetophenones undergo facile cyclization to indenone derivatives upon treatment with catalytic quantities of Rh(II) carboxylates.A variety of structural influences were encountered by varying the nature of the substituent group attached to the alkyne carbon atom.The cyclization reaction involves addition of a rhodium stabilized carbenoid onto the acetylenic ?-bond to generate a vinyl carbenoid.The vinyl carbenoid was found to undergo both CH and CC migration as well as δ-CH insertion into the alkyl backbone.Different catalysts were shown to result in significant variation in the product ratios for these reactions.Treatment of o-(5-(allyloxy)-1-pentynyl)-α-diazoacetophenone with rhodium(II) mandelate afforded 2-(2-propen-1-yl)-2-(1-oxo-1H-indenyl)-2,3,4,5-tetrahydrofuran in high yield.The formation of this compound involves initial formation of a vinyl carbenoid which reacts with the neighboring oxygen atom to give an oxonium ylide which subsequently undergoes a 2,3-sigmatropic rearrangement.When 2-ethynyl-α-diazoacetophenone is used, only products derived from 6-endo closure are observed.Substituted o-alkynyl α-diazoacetophenones give products derived from 5-exo cyclization.The mode of ring closure is controlled by both steric and electronic factors.