Intermolecular Carbophosphination of Alkynes with Phosphole Oxides via Ni-Al Bimetal-Catalyzed C-P Bond Activation.

Intermolecular carbophosphination reaction of alkynes or alkenes with unreactive C-P bonds remains an elusive challenge. Herein, we used a Ni-Al bimetallic catalyst to realize an intermolecular carbophosphination reaction of alkynes with 5-membered phosphole oxides, providing a series of 7-membered phosphepines in up to 94 % yield.

Chemical Glycosylation with -Methoxyphenyl (PMP) Glycosides via Oxidative Activation.

A novel persulfate-mediated oxidative glycosylation system using -methoxyphenyl (PMP) glycosides as bench-stable glycosyl donors is developed. This study shows that both KSO as an oxidant and Hf(OTf) as a Lewis acid catalyst play important roles in the oxidative activation of the PMP group into a potential leaving group. This convenient glycosylation protocol proceeds under mild conditions and delivers a wide range of biologically and synthetically valuable glycoconjugates, including glycosyl fluorides.

Novel indole and triazole based hybrid molecules exhibit potent anti-adipogenic and antidyslipidemic activity by activating Wnt3a/β-catenin pathway.

Obesity and dyslipidemia is the two facet of metabolic syndrome, which needs further attention. Recent studies indicate triazole and indole derivatives have remarkable anti-obesity/antidyslipidemic activity. To harness the above-mentioned potential, a series of novel triazole clubbed indole derivatives were prepared using click chemistry and evaluated for anti-adipogenic activity.

Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether.

Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units. The apparent vinylnickel intermediate was successfully trapped by the Michael electrophiles to get defined tri- and tetra-substituted olefins. An interesting selectivity switch was observed with internal alkynes.

BF3·OEt2-mediated syn-selective Meyer-Schuster rearrangement of phenoxy propargyl alcohols for Z-β-aryl-α,β-unsaturated esters.

Synthesis of Z-β-aryl-α,β-unsaturated esters from readily available 1-aryl-3-phenoxy propargyl alcohols is achieved via a BF3-mediated syn-selective Meyer-Schuster rearrangement under ambient conditions. The reaction mechanism is postulated to involve an electrophilic borylation of an allene intermediate as the key step to kinetically control the stereoselectivity.

N-Substitution dependent stereoselectivity switch in palladium catalyzed hydroalkynylation of ynamides: a regio and stereoselective synthesis of ynenamides.

A highly general palladium catalysed regioselective hydroalkynylation of ynamides for versatile enamide building blocks with an alkyne tether is achieved with an N-substitution dependent stereoselectivity switch under very mild reaction conditions.

Palladium-catalyzed regio- and stereoselective cross-addition of terminal alkynes to ynol ethers and synthesis of 1,4-enyn-3-ones.

Conjugated enynes, enol ethers, and enynones are versatile building blocks that can be elaborated by a wide variety of synthetic transformations. The selective synthesis of such units is a prerequisite for their effective utilization. The synthesis of conjugated 2-phenoxyenynes through a palladium-catalyzed cross-addition of terminal alkynes to phenylethynyl ethers (hydroalkynylation) is now presented.

Palladium-catalyzed tandem intramolecular oxy/amino-palladation/isocyanide insertion: synthesis of α-benzofuranyl/indolylacetamides.

A novel palladium-catalyzed approach to 2-benzofuranyl/indolylacetamides from 1-(o-hydroxy/aminophenyl)propargylic alcohols and isocyanides is described. The reaction proceeds through a cascade that includes oxy/aminopalladation, isocyanide insertion, and 1,4-hydroxyl migration. No oxidant or ligand is needed to promote the cascade, and the reactions are carried out under mild conditions to afford the products through high functional tolerance.

Synthesis of substituted 3-iodocoumarins and 3-iodobutenolides via electrophilic iodocyclization of ethoxyalkyne diols.

A convenient and general synthesis of various 4-substituted 3-iodocoumarins and 4,5-disubstituted 3-iodobutenolides is described via an exclusive 6-endo-dig iodocyclization of 3-ethoxy-1-(2-alkoxyphenyl)-2-yn-1-ols and 5-endo-dig iodocyclization of 1-alkoxy-4-ethoxy-3-yn-1,2-diols, respectively. The reaction is carried out under very mild conditions using I2 in CH2Cl2 or toluene at room temperature. Oxygens in OMe and OMOM groups were used as efficient nucleophiles for this intramolecular cyclization to obtain the products in good to excellent yields.