49836-17-1

Upstream product

• 29767-96-2 1-(pyridin-2-ylethynyl)cyclohexanol 
• 109-04-6 2-bromo-pyridine 
• 931-49-7 1-ethenylcyclohexene 
• 1945-84-2 2-ethynylpyridine 
• 109-09-1 2-chloropyridine 
• 4930-98-7 pyrid-2-ylhydrazine 
• 110-86-1 pyridine 
• 108-94-1 cyclohexanone 

Relevant academic research and scientific papers

Visible-light induced copper(i)-catalysed denitrogenative oxidative coupling of hydrazinylpyridines with terminal alkynes

Visible light mediated copper catalysed denitrogenative oxidative coupling of 2-hydrazinopyridines with terminal alkynes to form 2-(alkyl/arylethynyl) pyridines in the presence of O2 at room temperature is reported with 42 examples. This is the first report on visible light stimulated N2 elimination by an in situ generated copper(ii) superoxo/peroxo complex. N2 and water are the only by-products. The green chemistry metrics evaluation signifies that the current method is ecofriendly and economically feasible. This method allows the green synthesis of mGluR5 receptor antagonists, 2-methyl-6-(phenylethynyl)pyridine (MPEP) and 2-((3-methoxyphenyl)ethynyl)-6-methylpyridine (M-MPEP).

Transition-metal-free BF3-mediated oxidative and non-oxidative cross-coupling of pyridines

We report a BF3-mediated direct alkynylation of pyridines at C(2) by using a variety of alkynyllithium reagents (oxidative cross-coupling). Moreover, we have developed a novel transition-metal-free cross-coupling method between alkylmagnesium reagents and 4-substituted pyridines, such as isonicotinonitrile and 4-chloropyridine, by employing BF3· OEt2 as a promoter. The combination of these methods enabled us to efficiently prepare a range of di-, tri-, and tetrasubstituted pyridines. Oxidative or non-oxidative - That is the question! Pyridines bearing a substituent at position 4 readily undergo a BF3-mediated oxidative coupling at position 2 with a wide range of alkynyllithium compounds. In contrast, 4-cyano- or 4-chloropyridines undergo a novel BF3-mediated cross-coupling at position 4 with alkylmagnesium reagents. The combination of the two transition-metal-free procedures allows the preparation of a broad range of pyridines.

Heck alkynylation (copper-free sonogashira coupling) of aryl and heteroaryl chlorides, using Pd complexes of t -Bu2(p -NMe2C 6H4)P: Understanding the structure-activity relationships and copper effects

L2Pd(0) and L2Pd(II) complexes, where L= t-Bu 2(p-NMe2C6H4)P, have been identified as efficient catalyst systems for the Heck alkynylation of a variety of aryl bromides (17 examples) and aryl/heteroaryl chlorides (31 examples) with a range of aryl- and alkyl-acetylenes in excellent yields, under relatively low Pd loadings. The single-crystal X-ray structure determination of the presumably active catalytic species, L2Pd(0), was carried out in this study to better understand the superior activity of the current catalyst system from a structure-activity relationship point of view. The P-Pd-P bond angle indicates that the complex is bent (174.7) in comparison to the perfectly linear (180.0) structure of the analogous Pd(t-Bu3P)2. Preliminary mechanistic studies on the negative copper effect and substrate effect of aryl acetylenes were conducted to better understand the cross-coupling pathway of Heck alkynylation.

A highly efficient, practical, and general route for the synthesis of (R3P)2Pd(0): Structural evidence on the reduction mechanism of Pd(II) to Pd(0)

(Equation Presented). A highly efficient, practical, and general method was developed to synthesize a family of (R3P)2Pd(0) complexes, using a stoichiometric amount of phosphine ligands and readily available Pd(II) precursors. The st

Palladium-catalysed alkynylation of 2- or 3-bromopyridine

2- or 3-Alkynylpyridines were prepared using a palladium complex, in the absence of copper ions or amines. The mild procedure tolerated a range of 1-alkynes giving 2- or 3-alkynylpyridine in moderate to good yield.

Cyclohexenyl- and dehydropiperidinyl-alkynyl pyridines as potent metabotropic glutamate subtype 5 (mGlu5) receptor antagonists

Structure-activity relationship studies leading to the discovery of novel mGlu5 receptor antagonists are described. These compounds show high in vitro potency, have good in vivo receptor occupancy, and a reasonable intravenous pharmacokinetic profile.