Aryl 2- pyridyl

Aryl(2-pyridyl)methanes are obtained from coupling of picolyl diisopropyl carbinol with ArCl. The reaction involves fragmentation to form aryl(2-methylene-l,2-dihydropyridyl)-paUadium intermediates. ... 

Dehydrogenation of a-pyridinealdehyde hydrazone (251) yields not a-pyridyldiazomethane (252) but the cyclic isomer l,2,3-triazolo[3,4-a]pyridine (253).1 A similar ring closure is observed in diazo group transfers onto alkyl or aryl(2-pyridyl)methyl ketone (254) in MeOH/KOEt.1 The diazo intermediate could not be isolated but 3-acyl[l,2,3]triazolo[3,4-a]pyridine (255) is obtained.1... 

Dimethylaminoethyl ethers (IX-284) are obtained when aryl 2-pyridyl carbinols are treated with ( dimethylainino)ethyl chloride. For example. 

Dolzhenko et al. S5mthesized 12new fluorinated 7-aryl-2-pyridyl-6,7-dihydro[l,2,4] triazolo[l,5-a][l,3,5]triazin-5-amines 153 via three-step procedure starting from (iso) nicotinic hydrazides [134]. 

Scheme 8.13 Rhodium-catalysed borylation of aryl 2-pyridyl ethers.

In addition, 2-aryl pyridyl indazoles have been reported in the patent literature [25]. For example, compound 13 is reported to inhibit AKT-1 (IC50 < 0.18 pM). No kinase selectivity data were presented. 

The chiral center most frequently encountered is the asymmetric carbon atom, a tetrahedral C atom, bonded to four different substituents. Chiral centers of this type are known for many other elements (4). However, chiral centers are also found in other polyhedra, e.g., the metal atoms in octahedral compounds containing three bidendate chelate ligands. Chirality axes, present in the atrop isomers of ortho-substituted biaryls, occur in coordination chemistry in appropriately substituted aryl, pyridyl, and carbene metal complexes. Well known examples of planar chirality in organometallic chemistry are ferrocenes, cymantrenes, and benchrotrenes containing two different substituents in 1,2- or 1,3-positions relative to each other (5-5). 

Silylation of benzyl C-H bonds using hydrosilanes can also be performed with the aid of Ru3(CO)12-catalyst (Table 1) [9]. This silylation occurs only at benzylic CH3 groups. Pyridine, pyrazole, and hydrazones function as good directing groups. Benzylamines, oxime ethers, dimethylanilides, and aryl pyridyl ethers have no activity in this silylation. 

R = aryl, pyridyl, furanyl, thiophenyl r2 = r3 = H, primary, secondary amines... 

Brorno-1,2-i.sothiazoline-3-one Alkenyl, alkynyl, aryl, pyridyl A and variants [171]... 

R1-5 are H, halogen, alkyl, alkoxy, aryloxy, benzoyl, or aryl groups and R is (ar)alkyl, aryl, pyridyl, or these groups substituted by alkyl, aryl, alkoxy, or aryloxy... 

The aryl pyridyl ketone 66 cannot be formed by triazolo ring opening in basic medium. It has been proposed that the cationic intermediate formed in the catalytic cycle is in equilibrium with an azonium form, which with traces of water loses nitrogen, then a probable extrusion of Pd gives an alcohol, which is rapidly oxidized to ketone by air (Scheme 12). 

Alkyl and aryl pyridyl disulfide-W oxides are also effective sulfenylating agents. Thus, treatment under prolonged reaction time of 2,2 -dipyridyl disulfide-)V,) -dioxide with 2 equiv of thiol generates s)mimetrical disulfides and 7V hydroxy-2-thiopyridone as shown in eq 3. ... 

It has been mentioned that cis-trans isomerism has been observed in the stilbazoles (pp. 122, 334, 336). Examples are fairly common3i2-3 Hydrogenation over Lindlar s catalyst of aryl-pyridyl- or dipyridyl-acetylenes gives the m-stilbazoles or rw-l,2-dipyridylethylenes i4 5. rw-Stilbazoles readily form the /m -isomers when heated or irradiated with iodine, or heated with palladized charcoaU a, 3i3, 3i5 ... 

Useful products are also obtained by oxidizing alkyl and aryl pyridyl sulphides. With hydrogen peroxide, 2-methylthiopyridine and 6-methyl-thionicotinamide give the sulphoxides, and perbenzoic acid produces the sulphoxide from 2-benzylthiopyridine <. Hydrolysis of the dibromide from 2-pyridyl sulphide gives the sulphoxide" . More commonly the oxidation of... 

The rhodium-catalyzed conversion of aryl pyridyl ethers into arylboronates has been achieved using an NHC-supported rhodium catalyst (Scheme 6.31) [62]. The main theme of this work was the use of rhodium complexes to promote the cleavage of the pyridyl ether fragment and borylation of the arene. The reaction was carried out at elevated temperatures and afforded moderate to good yields of the arylboronates. One of the most impressive aspects of this chemistry was its tolerance to a wide range of functional groups. Heteroaryl ethers as well as substrates bearing esters, amides, and even a free amine were successfully converted into arylboronates. If the substrate is appropriately functionalized, this would be a reasonable approach to the formation of arylboronates. 

R = Ph, 4-MeC6H4,4-Br-CeH4, Bn, c-octyl, c-hexyl R = aryl, pyridyl, BnO, SiEts, C02Et, CH2CH2CI... 

The cross-coupling of aromatic and heteroaromatic rings has been carried out extensively[555]. Tin compounds of heterocycles such as oxazo-lines[556,557], thiophene[558,559], furans[558], pyridines[558], and seleno-phenes [560] can be coupled with aryl halides. The syntheses of the phenylo.xazoline 691[552], dithiophenopyridine 692[56l] and 3-(2-pyridyl)qui-noline 693[562] are typical examples. 

A -l,3,4-Oxadiazoline-5-thione, 4-alkyl-2-(4-pyridyl)-biological activity, 6, 445 A -l,3,4-Oxadiazoline-5-thione, 2-aryl-reactions... 

The reaction conditions (neutral, acidic or basic) do have an affect on the regioselectivity of the reaction. Acidic reaction conditions have also been shown to preferentially provide one regioisomer over basic conditions for reactions of aryl hydrazines. Extensive studies with 2-perfluoroacylcycloalkanones and mono-substituted hydrazines were studied to determine the selectivity of various alkyl-, aryl-, and heteroaryl-substituted hydrazines. Reactions of the aryl hydrazine 21 with the trifluoromethyl-substituted cycloalkanone 22 under neutral conditions (methanol, reflux) gave a mixture of isomers 23 and 24, whereas the reaction of the pyridyl hydrazine 25 was shown to give exclusively 26. 

Bromoquinolines behave in the Suzuki reaction similarly to simple carbocyclic aryl bromides and the reaction is straightforward. Examples include 3-(3-pyridyl)quinoline (72) from 3-bromoquinoline (70) and 3-pyridylboronic acid (71) (91JOC6787) and 3-phenyl-quinoline 75 from substituted 3,7-dibromoquinoline 73 and (2-pivaloylaminophenyl)boronic acid 74 (95SC4011). Notice that the combination of potassium carbonate and ethanol resulted in debromination at the C(7) position (but the... 

Oxidation of 7-hydroxy- and 7-aryl-5-oxo-2,3-dihydro-5//-pyrido[l,2,3- f< ]-l,4-benzothiazine-6-carboxylates and 6-carboxamides with 3-chloroper-oxybenzoic acid in CH2CI2 yielded sulfoxides and sulfones, depending on the molar ratio of the substrate and oxidizing agent (00MIP7). A sulfoxide was prepared by the oxidation of ethyl (3S)-3-methyl-10-(2,6-dimethyl-4-pyridyl)-7-oxo-2,3-dihydro-7//-pyrido[l,2,3-<7c]-l,4-benzothiazine-6-carbox-ylate (OOMIPIO). 

CYANIDE-CATALYZED CONJUGATE ADDITION OF ARYL ALDEHYDES 4-(3-PYRIDYL)-4-OXOBUTYRONITRILE... 

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