Mercuric Triflate Research Articles

One-Step Synthesis of the 1-Azaspiro[5.5]undecane Skeleton Characteristic of Histrionicotoxin Alkaloids from Linear Substrates via Hg(OTf)2 -Catalyzed Cycloisomerization.

Histrionicotoxin (HTX) alkaloids isolated from the poison arrow frogs possess a unique structure characterized by a 1-azaspiro[5.5]undecane skeleton common to the HTX family. The unique molecular architecture of HTXs and the interest as potential target drugs have prompted synthetic chemists to promote the total synthesis so far. However, all of the synthetic strategies to access the 1-azaspiro[5.5]undecane framework of HTXs take a multistep approach from linear starting materials due to stepwise construction of either six-membered carbo- or azacycle. Herein, we report the direct one-step construction of the 1-azaspiro[5.5]undecane skeleton from linear amino ynone substrates bearing an N-methoxycarbonyl group utilizing our mercuric triflate (Hg(OTf)2 )-catalyzed cycloisomerization reaction. The utility of this novel methodology was demonstrated by the total and formal syntheses of HTX-235A and HTX-283A, respectively, from the azaspirocycle.

Tetrodotoxin Framework Construction from Linear Substrates Utilizing a Hg(OTf)2-Catalyzed Cycloisomerization Reaction: Synthesis of the Unnatural Analogue 11-nor-6,7,8-Trideoxytetrodotoxin.

In this contribution, we propose a new synthetic approach to tetrodotoxin (TTX), one of the most famous marine toxins that, after first preparing a functionalized linear substrate, forms a cyclohexane core from the substrate utilizing our mercuric triflate (Hg(OTf)2)-catalyzed cycloisomerization reaction. The concept was applied to the synthesis of 11-nor-6,7,8-trideoxyTTX and 11-nor-4,9-anhydro-6,7,8-trideoxyTTX, which are unnatural TTX analogues, demonstrating the validity of our new approach.

Synthesis of α-diketones from alkylaryl- and diarylalkynes using mercuric salts.

Both alkylarylalkynes and diarylalkynes 1 are converted into the α-diketones 2 in good yield by the use of mercuric salts, e.g., mercuric nitrate hydrate or mercuric triflate, in the presence of water. Other mercuric salts, e.g., sulfate, chloride, acetate, or trifluoroacetate, do not provide the diketone product. A possible mechanism is proposed.

ChemInform Abstract: Synthesis of Fused Tetrahydropyrans by Hydroalkoxylation of δ‐Hydroxy Allenes.

Abstract Fused tetrahydropyrans were synthesized by silver(I)- and mercury(II)-mediated intramolecular hydroalkoxylations of δ-hydroxy allenes installed on a tetrahydropyran template. Cyclization of simple allenes was promoted by silver perchlorate to afford vinyl-substituted trans-fused bis-tetrahydropyrans, whereas cyclization of methyl-substituted allenes at the internal allenic carbon atom was achieved more effectively with a catalytic amount of mercuric triflate rather than with silver salts.

Synthesis of fused tetrahydropyrans by hydroalkoxylation of δ-hydroxy allenes

Fused tetrahydropyrans were synthesized by silver(I)- and mercury(II)-mediated intramolecular hydroalkoxylations of δ-hydroxy allenes installed on a tetrahydropyran template. Cyclization of simple allenes was promoted by silver perchlorate to afford vinyl-substituted trans-fused bis-tetrahydropyrans, whereas cyclization of methyl-substituted allenes at the internal allenic carbon atom was achieved more effectively with a catalytic amount of mercuric triflate rather than with silver salts.

Mercuric Triflate

Mercuric Triflate

ChemInform Abstract: Carbon—Nitrogen Bond Formation Between Allyl Silyl Ether and Hydrazide Promoted by Mercuric Triflate Catalyst.

AbstractThe reaction proceeds under mild conditions without the use of any activating ligand or additive.

Carbon-Nitrogen Bond Formation between Allyl Silyl Ether and Hydrazide Promoted by Mercuric Triflate Catalyst

An efficient method for carbon–nitrogen bond formation between ally silyl ethers and <i>N</i>,<i>N</i>-acyltosylhydrazine was developed under very mild conditions using 2 mol% of mercuric triflate [Hg(OTf)₂] as a catalyst. This method does not require the use of any ligand system or supplementary additives and is applicable to the preparation of various <i>N</i>-allylhydrazides with good to excellent yields.

Terminal alkynes as keto-methyl equivalent toward one pot synthesis of 1,5-benzodiazepine derivatives under catalysis of Hg(OTf)2

Mercuric triflate catalyzes the reaction between 1,2-diaminobenzene and terminal alkynes to afford 2,4-disubstituted 2-methyl-2,3-dihydro-1H-benzo[b][1,4]diazepine in an excellent yield. The terminal alkynes function as a source of keto-methyl equivalent.

Intermolecular Amination of Allyl Alcohols with Sulfamates: Effective Utilization of Mercuric Catalyst

AbstractHerein, we describe the intermolecular amination of allyl alcohols with sulfamates, which have been underutilized as nitrogen nucleophiles for allylic amination. Methyl sulfamate is a good nucleophile in the presence of mercuric triflate and efficiently generates monoallylation products in excellent yield at room temperature. Furthermore, the solid‐supported mercuric catalyst silaphenyl mercuric triflate also showed remarkable catalytic activity for the allylic amination.

ChemInform Abstract: A New Catalyst for Organic Synthesis: Mercuric Triflate

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.

A new catalyst for organic synthesis: mercuric triflate

Herein, we describe Hg(OTf)(2) as a new catalytic system for organic synthesis, which can achieve the hydration of alkynes, C-C bond forming cyclizations, heterocycle synthesis and cyclization initiated by allylic alcohols at very high catalytic turnovers under mild conditions. The first solid-supported mercuric salt, silaphenylmercuric triflate, was also developed and found to act as a powerful catalyst for most Hg(OTf)(2)-catalyzed reactions.

Synthesis of (–)-Heliannuol E via Mercuric Triflate Catalyzed Arylene Cyclization

The third-generation synthesis of (-)-heliannuol E has been accomplished employing mercuric triflate catalyzed arylene cyclization as the key step.

Hg(OTf)2‐Catalyzed Cycloisomerization of 2‐Ethynylaniline Derivatives Leading to Indoles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Hg(OTf) 2-Catalyzed cycloisomerization of 2-ethynylaniline derivatives leading to indoles

Cycloisomerization of 2-ethynylaniline derivatives catalyzed by mercuric triflate afforded indole derivatives in excellent yield under mild reaction conditions with high catalytic turnover up to 100 times.

Mercuric Triflate Revisited: Development of Catalytic Reactions

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Hg(OTf) 2-Catalyzed cyclization of alkynyl tert-butylcarbonate leading to cyclic enol carbonate

Mercuric triflate was shown to be a powerful catalyst for the cyclization of alkynyl tert-butylcarbonates giving rise to cyclic enol carbonates under mild conditions. Internal alkynyl carbonate affords endo cyclization product selectively, while terminal alkynyl carbonate provides only exo cyclization product.

Mercuric Triflate Catalyzed Cycloisomerization of Alkynyl‐1,3‐cyclohexanedione and Alkynyl‐1,3‐cyclopentanedione.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Mercuric Triflate Catalyzed Reaction of Propargyl Acetates with Water Leading to Vinyl Ketones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Mercuric Triflate·3TMU Catalyzed Cyclization of ω-Alkynoic Acids and ­Synthesis of a Naturally Occurring γ-Methylene-γ-lactone

Hg(OTf) 2 ·3TMU showed efficient catalytic activity for the cyclization of (o-alkynoic acid to give co-methylene-co-lactone in excellent yield, and the procedure was efficiently applied for the synthesis of naturally occurring y-methylene-y-lactone. The absolute structure of the natural product was established by this synthesis.