153997-24-1

Upstream product

• 288-13-1 NH-pyrazole 
• 536-74-3 phenylacetylene 
• 103-64-0 bromostyrene 
• 637-44-5 phenylpropyolic acid 

Downstream Products

• 58416-69-6 1-phenethyl-1H-pyrazole 

Relevant academic research and scientific papers

A stereoselective organic base-catalyzed protocol for hydroamination of alkynes under solvent-free conditions

The hydroamination of alkynes is a straightforward and atom-economical process for the synthesis of substituted nitrogen-containing alkenes. Herein we report a novel protocol that involves for the first time solvent-free conditions (SolFC) and the use of an organic base, namely 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) to stereoselectively promote the process. The scope of this metal-free protocol has been evaluated through an extensive study that has led to the conclusion that in most cases the yield and stereoselectivity values are very high (14 examples, up to 95% yield, Z/E up to 99%).

Inorganic base-mediated stereoselective hydroamination of arylalkynes with imidazole: An efficient access to N-vinylimidazoles

A metal-free inorganic base-mediated highly stereoselective hydroamination of arylalkynes with imidazoles has been developed, and the corresponding N-vinylimidazoles were obtained in good yields and with moderate to excellent stereoselectivities (up to 99

Chemo-, regio-, and stereoselective n-alkenylation of pyrazoles/ benzpyrazoles using activated and unactivated alkynes

Transition-metal-free chemo-, regio-, and stereoselective synthesis of (Z) and (E) styryl pyrazoles and benzpyrazoles by the addition of N-heterocycles onto functionalized terminal and internal alkynes using a super basic solution of KOH/DMSO has been described. The stereochemical outcome of the reaction was governed by time and quantity of the base. The reaction of pyrazoles and benzpyrazoles onto alkynes takes place chemoselectively without affecting the free -NH2 group of pyrazoles and -OH group of alkynes. The designed protocol was well implemented on alkynes bearing long alkyl chain, an alicyclic ring, hydroxy, ether, and ester functionality, which offer the N-alkenylated products in good yields. This developed methodology also provides easy access for the synthesis of bis-vinylated heterocycles. The presence of free -NH2, -OH, -COOR, and halo group in styryl pyrazoles, could be further utilized for synthetic elaboration, which is advantageous for biological evaluation. For the first time, we have disclosed the base-mediated conversion of (Z)-styryl pyrazoles to (E)-styryl pyrazoles in KOH/DMSO system. The cis-rans isomerization was supported by the control experiments and deuterium labeling studies.

Structure-selectivity relationship in ruthenium-catalyzed regio- and stereoselective addition of alkynes to pyrazoles: An experimental and theoretical investigation

Ruthenium(II) complexes, [Ru(dppe)(PPh3)(CH3CN)2Cl][BPh4] {dppe = diphenylphosphinoethane} (1) and [Ru(dppp)2(CH3CN)Cl][BPh4] (2) {dppp = diphenylphosphinopropane}, are efficient catalysts for vinylation of pyrazoles by alkynes. While the 1-catalyzed reaction is trans-selective, the corresponding 2-catalyzed reaction is cis-selective. The experimental results have been rationalized by density functional theory calculations.

Transition-metal-free synthesis of N-(1-Alkenyl)imidazoles by potassium phosphate-promoted addition reaction of alkynes to imidazoles

The addition reaction of alkynes to N-heterocycles by simply heating in DMSO with potassium phosphate is reported. Good yields with high stereoselectivity could be achieved for a range of substrates. The scope is quite general for both amines and phenylac

Decarboxylative Hydroamination of 3-Arylpropiolic Acids with N-Heterocycles under Transition-Metal-Free Conditions

A decarboxylative hydroamination cascade reaction of 3-arylpropiolic acids with N-heterocycles under transition-metal-free conditions was developed. 3-Arylpropiolic acids were found to react smoothly with a range of N-heterocycles under the effect of t-BuOK to afford N-vinyl heterocycles in moderate to excellent yields. This reaction represents the first decarboxylative hydroamination of 3-arylpropiolic acids without the aid of a transition-metal catalyst. Georg Thieme Verlag Stuttgart, New York.

First application of an efficient and versatile ligand for copper-catalyzed cross-coupling reactions of vinyl halides with N-heterocycles and phenols

[Chemical equaction presented] 2-Pyridin-2-yl-1H-benzoimidazole L3 is presented as a new, efficient, and versatile bidentate N-donor ligand suitable for the copper-catalyzed formation of vinyl C N and C O bonds. This inexpensive and easily prepared ligand facilitates copper-catalyzed cross-coupling reactions of alkenyl bromides and Iodldes with N-heterocycles and phenols to afford the desired cross-coupled products In good to excellent yields with full retention of stereochemistry. This method is particularly noteworthy given Its efficiency, that is, mild reaction conditions, low catalyst loading, simplicity, versatility, and exceptional level of functional group tolerance.

Lewis acid catalyzed addition of pyrazoles to alkynes: Selective synthesis of double and single addition products

Silver and zinc salts were found to efficiently catalyze the addition of an N-H bond of pyrazoles to alkynes. With silver triflate as a catalyst, two pyrazoles regioselectively attacked the same carbon atom of the C≡C bond of aliphatic terminal alkynes to give gem-dipyrazolylalkanes predominantly. Replacement of silver triflate with zinc triflate allows us to achieve double addition of pyrazoles to aromatic terminal alkynes. In contrast to the selective double addition, the corresponding single addition of aliphatic and aromatic terminal alkynes exclusively proceeded in the presence of a catalytic amount of silver nitrate. Internal alkynes also participated in the single addition reaction with the aid of silver triflate as a catalyst. The notable feature of this protocol is the utilization of an addition reaction being optimal from environmental and atom-economical points of view. The reaction mechanism is also described. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.