78979-71-2

Upstream product

• 10160-87-9 Propiolaldehyde diethyl acetal 
• 27845-50-7 (E)-N-benzylidenebenzylamine 
• 2051-97-0 1-benzyl-1H-pyrrole 
• 591-50-4 iodobenzene 
• 4850-50-4 1-phenyl-butane-1,4-diol 
• 100-46-9 benzylamine 
• 1515-78-2 buta-1,3-dien-1-ylbenzene 
• 54838-91-4 6-phenyl-3,6-dihydro-2H-[1,2]oxazine 
• 100-39-0 benzyl bromide 
• 3042-22-6 2-phenyl-1H-pyrrole 
• 66003-76-7 Diphenyliodonium triflate 
• 107-21-1 ethylene glycol 
• 98-86-2 acetophenone 
• 536-74-3 phenylacetylene 

Relevant academic research and scientific papers

Direct C2-arylation ofN-acyl pyrroles with aryl halides under palladium catalysis

C2-arylation ofN-acyl pyrroles with aryl halides is developed for the first time using Pd(PPh3)4as a catalyst in combination with Ag2CO3under air, which allowed the application of a good compatibility catalytic system. This protocol provides a straightforward method for the preparation of valuable arylated pyrroles in moderate to good yields under the standard conditions with good substrate tolerance. Interestingly, whileN-benzoyl pyrroles reacted well, the use of substrates with a thiophene or furan ring indicated that the thiophene and furan rings are more reactive than pyrrole for the present catalytic system.

Sustainable Manganese-Catalyzed Solvent-Free Synthesis of Pyrroles from 1,4-Diols and Primary Amines

A general and selective metal-catalyzed conversion of biomass-derived primary diols and amines to the highly valuable 2,5-unsubstituted pyrroles has been developed. The reaction is catalyzed by a stable nonprecious manganese complex (1 mol %) in the absence of organic solvents whereby water and molecular hydrogen are the only side products. The manganese catalyst shows unprecedented selectivity, avoiding the formation of pyrrolidines, cyclic imides, and lactones.

Copper-catalyzed pyrrole synthesis from 3,6-dihydro-1,2-oxazines

Highly-functionalized pyrroles could be effectively synthesized from 3,6-dihydro-1,2-oxazines using a heterogeneous copper on carbon (Cu/C) under neat heating conditions. Furthermore, the in situ formation of 3,6-dihydro-1,2-oxazines via the hetero Diels-Alder reaction between nitroso dienophiles and 1,3-dienes and the following Cu/C-catalyzed pyrrole synthesis also provided the corresponding pyrrole derivatives in a one-pot manner.

Selective synthesis of pyrrolo[1,2-a] azepines or 4,6-dicarbonyl indoles via tandem reactions of alkynones with pyrrole derivatives

Novel methodologies for the selective synthesis of pyrrolo[1,2-a]azepines or 4,6-dicarbonyl indoles starting from pyrrole derivatives and alkynones are described. When reactions were carried out with 1,2,4-trisubstituted N-propargyl pyrroles using a ZnI2 catalyst, pyrrolo[1,2-a]azepines were obtained. Whereas 4,6-dicarbonyl indoles were produced selectively with 1,2-disubstituted pyrroles in the presence of silica gel. The reaction outcomes depend on the substituent pattern of the substrates and the nature of the catalysts chosen. Control reactions suggested that the formation of a conjugated enamine intermediate was crucial for both the processes. With easily accessible starting materials, inexpensive catalysts and an easy-to-handle procedure, this reaction has the potential to become a general protocol for the synthesis of pyrrolo[1,2-a]azepines or indoles.

Leveraging the micellar effect: Gold-catalyzed dehydrative cyclizations in water at room temperature

The first examples of gold-catalyzed cyclizations of diols and triols to the corresponding hetero- or spirocycles in an aqueous medium are presented. These reactions take place within nanomicelles, where the hydrophobic effect is operating, thereby driving the dehydrations, notwithstanding the surrounding water. By the addition of simple salts such as sodium chloride, reaction times and catalyst loadings can be significantly decreased.

Multicomponent reactions in PEG-400: Ruthenium-catalyzed synthesis of substituted pyrroles

An efficient and eco-friendly method for the synthesis of substituted pyrroles has been developed via ruthenium-catalyzed multicomponent reaction of ketone, amine, and ethylene glycol in PEG-400 as solvent medium without using any external ligand. The cat

Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates

Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.

An extremely facile synthesis of furans, pyrroles, and thiophenes by the dehydrative cyclization of propargyl alcohols

Furans, pyrroles, and thiophenes are efficiently prepared by gold-catalyzed dehydrative cyclizations of readily available, heteroatom-substituted propargyllc alcohols. The reactions are rapid, high-yielding, and procedurally simple, giving essentially pure aromatic heterocycles In minutes under open-flask conditions with catalyst loadings as low as 0.05 mol %.

Synthesis of N-substituted 2-arylpyrroles by the reaction of (η2-imine)titanium complexes with 3,3-diethoxypropyne

(η2-Imine)Ti(O-i-Pr)2 complexes generated from arylaldehyde imines and a divalent titanium reagent, Ti(O-i-Pr)4/2i-PrMgCl, reacted with 3,3-diethoxypropyne to afford 2-arylpyrroles.

Electrocyclization reactions of 1-Aza- and 1-oxapentadienyl and -heptatrienyl cations: Synthesis of pyrrole and furan derivatives

Quantum chemical DFT calculations (B3LYP/6-31+G) have been used to gain insight into the conformational and energy properties of the 1-aza- and 1-oxapentadienyl and -heptatrienyl cations 1, 2, 3, and 4. The calculated thermodynamic and kinetic data of the ring-closure reactions giving the cyclic products 5-14 are reported and discussed with respect to the experimental results. Experimentally, synthetic routes to the α,β-unsaturated carbonyl compounds 24 and 27, each with a leaving group in the γ-position, have been developed. These compounds have been investigated with respect to their ability to undergo 1,5-electrocyclization reactions to yield 2,5-disubstituted furans 28 upon heating in the presence of acid, presumably through the intermediate formation of the 1-oxapentadienyl cations 2. From the corresponding imine 29a the pyrrole 30d was obtained after treatment with tetrakis (triphenylphosphane) palladium. In the presence of benzylamine and the Pd° catalyst, the corresponding pyrroles 30a-c were formed from 24 and 27. The homologous α,β,γ,δ-unsaturated carbonyl compounds 31 afforded 2-vinyl-substituted furans 32 upon heating with acid, and the 2-vinyl-substituted pyrroles 34 on treatment with benzylamine and the Pd catalyst. No seven-membered heterocyclic rings were formed. Surprisingly, the α,β-unsaturated carbonyl compounds with two phenyl substituents at the γ-position also provided pyrrole derivatives 40 through a formal dimerization. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.