Benzyl Phenyl Ketone Research Articles

Mechanistic Comparison of the Nickel(0)-Catalyzed Homo-Oligomerization and Co-Oligomerization of Alkynes and Nitriles

A comparative mechanistic study of the nickel(0)-catalyzed homo-oligomerization and co-oligomerization of alkynes and of nitriles has been undertaken, with diphenylacetylene and benzonitrile, towards an array of nickel(0) reagents, such as finely divided nickel, (COD)2Ni, (Bpy)(COD)Ni, (Et3P)4Ni, (Bpy)(PhC≡CPh)Ni and (COD)2Ni−MeAlCl2 combinations in donor (THF) and nondonor (PhMe or neat substrate) solvents. Special attention has been given to the detailed molecular structures of the initial 1:1 adducts, (Bpy)(PhC≡CPh)Ni, (Ph3P)3(PhC≡CPh)Ni and [(Ph3P)(PhC≡N)Ni]4 by a consideration of XRD and IR data. Data from the single crystal XRD analysis of (Bpy)(PhC≡CPh)Ni, reported here for the first time, are shown to be in excellent accord with the presence of a 2,3-diphenylnickelacyclopropene ring for the (PhC≡CPh)Ni moiety with almost coplanar chelating coordination of the bipyridyl ligand, rather than with the presence of simple “side-on” coordination of the alkyne with the metal center. A parallel analysis of XRD and IR data for the two benzonitrile-nickel(0) complexes, which were drawn from previous publications, has concluded that the nickel in (Ph3P)3(PhC≡N)Ni is coordinated in an “end-on” fashion and the nickel centers in [(Ph3P)(PhC≡N)Ni]4 are coordinated as bridges between nitrile units in both an “end-on” and “side-on” manner. The stereochemistry of the acid hydrolysis of the nickelacyclopropene complex to (E)- or (Z)-alkene was shown to depend on the structure of the cleaving acid; parallel hydrolysis of nitrile-nickel complexes has shown that “end-on” complexes regenerate the nitrile, while “side-on” complexes lead to the aldehyde. In homo-oligomerization of diphenylacetylene or other alkyne the clean cyclotrimerization to the benzene derivative was shown to proceed by way of a nickelacyclopentadiene intermediate, as was evident by chemical trapping. The homo-oligomerization of benzonitrile by nickel(0) was found not to lead to 2,4,6-triphenyl-1,3,5-triazine, as claimed in the literature, but rather solely to benzyl phenyl ketone, the dimeric hydrolysis product. The attempted co-oligomerization of diphenylacetylene and benzonitrile with ordinary nickel(0) complexes led only to the homocyclotrimer of the alkyne. Only when the alkyne was prebonded to the nickel, as in (Bpy)(PhC≡N)Ni, could significant amounts of a codimerization product with the nitrile be observed. The origin of the triazine, claimed in a previous report to form from benzonitrile and Raney nickel, has been traced to the presence of adventitious moisture and air. Other unexpected products formed from nickel(0) complexes and benzonitrile have been shown to arise from oxidative addition reactions of nickel(0) with various σ C−E bonds.

Mechanistic Comparison of the Nickel(0)-Catalyzed Homo-Oligomerization and Co-Oligomerization of Alkynes and Nitriles

A comparative mechanistic study of the nickel(0)-catalyzed homo-oligomerization and co-oligomerization of alkynes and of nitriles has been undertaken, with diphenylacetylene and benzonitrile, towards an array of nickel(0) reagents, such as finely divided nickel, (COD)2Ni, (Bpy)(COD)Ni, (Et3P)4Ni, (Bpy)(PhC≡CPh)Ni and (COD)2Ni−MeAlCl2 combinations in donor (THF) and nondonor (PhMe or neat substrate) solvents. Special attention has been given to the detailed molecular structures of the initial 1:1 adducts, (Bpy)(PhC≡CPh)Ni, (Ph3P)3(PhC≡CPh)Ni and [(Ph3P)(PhC≡N)Ni]4 by a consideration of XRD and IR data. Data from the single crystal XRD analysis of (Bpy)(PhC≡CPh)Ni, reported here for the first time, are shown to be in excellent accord with the presence of a 2,3-diphenylnickelacyclopropene ring for the (PhC≡CPh)Ni moiety with almost coplanar chelating coordination of the bipyridyl ligand, rather than with the presence of simple “side-on” coordination of the alkyne with the metal center. A parallel analysis of XRD and IR data for the two benzonitrile-nickel(0) complexes, which were drawn from previous publications, has concluded that the nickel in (Ph3P)3(PhC≡N)Ni is coordinated in an “end-on” fashion and the nickel centers in [(Ph3P)(PhC≡N)Ni]4 are coordinated as bridges between nitrile units in both an “end-on” and “side-on” manner. The stereochemistry of the acid hydrolysis of the nickelacyclopropene complex to (E)- or (Z)-alkene was shown to depend on the structure of the cleaving acid; parallel hydrolysis of nitrile-nickel complexes has shown that “end-on” complexes regenerate the nitrile, while “side-on” complexes lead to the aldehyde. In homo-oligomerization of diphenylacetylene or other alkyne the clean cyclotrimerization to the benzene derivative was shown to proceed by way of a nickelacyclopentadiene intermediate, as was evident by chemical trapping. The homo-oligomerization of benzonitrile by nickel(0) was found not to lead to 2,4,6-triphenyl-1,3,5-triazine, as claimed in the literature, but rather solely to benzyl phenyl ketone, the dimeric hydrolysis product. The attempted co-oligomerization of diphenylacetylene and benzonitrile with ordinary nickel(0) complexes led only to the homocyclotrimer of the alkyne. Only when the alkyne was prebonded to the nickel, as in (Bpy)(PhC≡N)Ni, could significant amounts of a codimerization product with the nitrile be observed. The origin of the triazine, claimed in a previous report to form from benzonitrile and Raney nickel, has been traced to the presence of adventitious moisture and air. Other unexpected products formed from nickel(0) complexes and benzonitrile have been shown to arise from oxidative addition reactions of nickel(0) with various σ C−E bonds.

An EPR investigation of persistent radicals from the photolysis of p, p'-dialkyl-substituted phenyl benzyl ketones adsorbed on MFI zeolites

The photolysis of isomeric pairs of p,p'-dialkyl-substituted phenyl benzyl ketones adsorbed on MFI zeolites has been investigated by EPR spectroscopy. Photolysis produces persistent "benzoyl type" and "benzyl type" radicals. The dominant persistent radical produced by photolysis of any particular isomeric pair depends on the length and position of the p-alkyl chain. The results are attributed to supramolecular stereoisomers resulting from preferential adsorption of the longer alkyl chain into the pores of the zeolite.

Palladium-Catalyzed Cross-Coupling of Benzyl Ketones and α,β-Unsaturated Carbonyl and Phenolic Compounds with o-Dibromobenzenes to Produce Cyclic Products

Abstract A number of carbonyl and phenolic compounds efficiently couple with o-dibromobenzenes in the presence of a palladium catalyst and a base to give the corresponding oxygen-containing heterocycles or carbocyclic compounds. Thus, from the reactions of benzyl phenyl ketones, 1-naphthols, and α,β-unsaturated aldehydes and ketones, benzofuran, benzopyran, benzocyclobutane, and indene derivatives, respectively, are produced selectively via the successive formation of C–C and C–O bonds or of two C–C bonds.

ChemInform Abstract: Palladium‐Catalyzed Multiple Arylation of Phenyl Ketones with Aryl Bromides

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Palladium-catalyzed multiple arylation of phenyl ketones with aryl bromides

Abstract Benzyl phenyl ketones undergo triarylation upon treatment with excess aryl bromides in the presence of a catalytic amount of ce:simple-parad(PPh 3 ) 4 and Cs 2 CO 3 as base in o -xylene on the α- and two ortho -positions of the carbonyl group to give diphenymethyl 2,6-diphenylphenyl ketone derivatives as the predominant products. Acetophenone and diphenylmethyl phenyl ketone similarly undergo tetra- and diarylations, respectively.

The Influences of Organic Additives on Zinc Electrocrystallization from KCl Solutions

The effects of some conventional additives such as triton X‐10 (TX‐10), sodium methylene bis(naphthalene sulfonate) (NNO), phenylbenzylketone (PBK), and a CH‐1 brightener on the electrodeposition of zinc onto the glassy carbon electrode were examined using chronoamperometry. The surface morphology, grain size, and texture of the deposits were characterized by scanning electron microscope, transmission electron microscope, and X‐ray diffraction. It was found that the electrocrystallization mechanisms of zinc and microstructure of deposits are sensitive to the identity of organic additives. On one hand, in the absence of additive or in the presence of NNO or PBK, zinc deposition proceeds by three‐dimensional instantaneous nucleation and growth, while in the presence of TX‐10 or a CH‐1 brightener, zinc deposition follows the three‐dimensional progressive nucleation and growth. On the other hand, in the absence of additive, the deposit forms a loose and porous structure with no texture. In the presence of PBK and TX‐10, the deposits are (101) and (110) texture, respectively. And in the presence of a CH‐1 brightener, deposit is smooth and bright and forms a (101) and (110) texture, where a homogeneous distribution of small 8 nm grains appears. These facts show that the effects of a CH‐1 brightener on the zinc electrodeposition mainly result from the combinational action of TX‐10 and PBK. In addition, we also found that surface morphology of deposits is strongly correlated to deposit texture. © 1999 The Electrochemical Society. All rights reserved.

ORGANOPHOSPHOROUS CHEMISTRY: SELECTIVE TRANSFORMATION OF BENZOIN TO BENZIL, DESYL BROMIDE, OR BENZYL PHENYL KETONE

Reaction of benzoin with dibromotriphenylphosphorane under various conditions has been closely investigated. Benzoin was selectively converted to desyl bromide by treatment with dibromotriphenylphosphorane in the presence of triethylamine, while benzyl phenyl ketone was formed in the presence of an excess amount of triphenylphosphine. On the other hand, benzoin was effectively oxidized to bend by treatment with only bromine. The mechanism of producing these was also proposed. Desyl bromide was formed from the reaction of benzoin with dibromotriphenylphosphorane as a primary product and converted to benzyl phenyl ketone via the Perkow reaction, and benzil was formed by the oxidation of benzoin by bromine. When triethylamine or triphenylphosphine was used as an added base, these bases trapped free bromine, and the oxidation product, benzil, was formed in low yield. In the presence of triphenylphosphine as a base, the Perkow reaction of desyl bromide proceeded smoothly to give benzyl phenyl ketone preferentially, while in the presence of triethylamine, replacement of the hydroxy group to bromide occurred mainly.

Lipase-catalysed selective deacetylation of phenolic/enolic acetoxy groups in peracetylated benzyl phenyl ketones

Highly chemo- and regioselective de-esterification has been observed in the deacetylation of peracetylated enolic forms of polyphenolic benzyl phenyl ketones by lipase from porcine pancreas (PPL) suspended in tetrahydrofuran (THF). The enzyme selectively deacetylates the enolic acetoxy over the phenolic acetoxy group(s) and continuation of the reaction resulted, in addition the regioselective deacetylation of acetoxy function para to the nuclear carbonyl group.

Carbon-Carbon Bond Cleavage of .ALPHA.-Substituted Benzoins by Retro-Benzoin Condensation; A New Method of Synthesizing Ketones.

When α-benzylbenzoin (3a, α-benzyl-α-hydroxybenzyl phenyl ketone) was treated with potassium cyanide (1) in N, N-dimethylformamide at 80°C for 1 h, the carbon-carbon bond was cleaved, resulting in the formation of deoxybenzoin (4a, benzyl phenyl ketone) and benzaldehyde (2a). This carbon-carbon bond cleavage proceeds through a retro-benzoin condensation mechanism. This mothod of synthesizing ketones was applied to several α-substituted benzoins (3), and the corresponding ketones (4) were formed in good yields. Further, we found that the cyanide ion-donating ability of tetrabutylammonium cyanide (6, Bu4NCN) is more effective than that of potassium cyanide (1, KCN). As expected from the chemical analogy between cyanide ion and azolium ylide, serveral azolium salts (7) can also be employed in the retro-benzoin condensation as catalysts.The benzoin derivatives 3 were synthesized in the following three ways; reaction of alkyl halide (9) with benzoin (5), Michael addition of benzoin (5) with acceptors (10), and Grignard reaction of benzils (8). Alkylation of the benzoins without isolation, followed by carbon-carbon bond cleavage, readily afforded the corresponding ketones (4).

Electrochemical reduction of O-acylated aldehyde cyanohydrins

Cyanohydrins of aromatic aldehydes, acylated at the hydroxyl group, are reducible in aprotic medium; the base generated during the reduction induces a rearrangement of the compound to a vicinal diketone. Thus, O-benzoyl benzaldehyde cyanohydrin ( 1) is rearranged during the reduction to benzil and O-acetyl benzaldehyde cyanohydrin to 1-phenylpropane-1,2-dione; on the cyclic voltammetric curves of the acylated cyanohydrins the radical anion of the diketone gives an anodic peak on the reverse sweep and the diketone a cathodic peak on the second negative sweep. The reduction of the diketones occurs at a higher potential than that of the O-acyl benzaldehyde cyanohydrin and the diketone is therefore reduced further at the potential used for the reduction of the acylated benzaldehyde cyanohydrin. Thus both benzil and O-benzoyl benzaldehyde cyanohydrin yield on reduction the same main product, benzyl phenyl ketone; besides that, 1 gives minor amounts of benzylcyanide and benzoic acid. Possible reaction routes are discussed.

Diazo‐Transfer Reaction with Diphenyl Phosphorazidate

AbstractDiphenyl phosphorazidate (DPPA) was used as the azide source in a one‐pot synthesis of 2,2‐disubstituted 3‐amino‐2H‐azirines 1 (Scheme 1). The reaction with lithium enolates of amides of type 2, bearing two substituents at C(2), proceeded smoothly in THF at 0°; keteniminium azides C and azidoenamines D are likely intermediates. Under analogous reaction conditions, DPPA and amides of type 3 with only one substituent at C(2) gave 2‐diazoamides 5 in fair‐to‐good yield (Scheme 2). The corresponding 2‐diazo derivatives 6–8 were formed in low yield by treatment of the lithium enolates of N,N‐dimethyl‐2‐phenylacetamide, methyl 2‐phenylacetate, and benzyl phenyl ketone, respectively, with DPPA. Thermolysis of 2‐diazo‐N‐methyl‐N‐phenylcarboxamides 5a and 5b yielded 3‐substituted 1,3‐dihydro‐N‐methyl‐2H‐indol‐2‐ones 9a and 9b, respectively (Scheme 3). The diazo compounds 5–8 reacted with 1,3‐thiazole‐5 (4H)‐thiones 10 and thiobenzophenone (13) to give 6‐oxa‐1,9‐dithia‐3‐azaspiro[4.4]nona‐2,7‐dienes 11 (Scheme 4) and thiirane‐2‐carboxylic acid derivatives 14 (Scheme 5), respectively. In analogy to previously described reactions, a mechanism via 1,3‐dipolar cycloaddition, leading to 2,5‐dihydro‐1,3,4‐thiadiazoles, and elimination of N2 to give the ‘thiocarbonyl ylides’ of type H or K is proposed. These dipolar intermediates with a conjugated CO group then undergo either a 1,5‐dipolar electrocyclization to give spirohetrocycles 11 or a 1,3‐dipolar electrocyclization to thiiranes 14.

Regioselective enzyme-catalyzed deacetylation of benzyl phenyl ketone peracetates in organic solvents

Lipases from porcine pancreas and Candida cylindracea, suspended in different organic solvents have been used to deacetylate peracetates of benzyl phenyl ketones (desoxybenzoins). High regioselectivity in the reactions has been observed, also the nature of the solvent affects the rate of the reaction.

Synthesis and study of mesogenic compounds having a methylene ketone (-CH2-CO-) linking group

Abstract Recently we have reported isoflavone derivatives as potential mesogens [1]. During the synthesis of isoflavone derivatives, 2,4-dihydroxyphenyl benzyl ketone was synthesized as an intermediate. Nguyen Huu Tinh et al. [2] have reported the effect of the influence of the central linkage, such as ethylene, methylene ketone and ketone on the mesogenic compounds. Vora et al. [3] have also reported a mesogenic homologous series with terminal and lateral phenolic groups. To understand the effect of hydrogen bonding originating between methylene ketone and free lateral hydroxy groups, ortho to the methylene ketone group, on mesogenicity, the present homologous series of 2-hydroxy, 4(4′-n-alkoxybenzoyloxy)phenyl benzyl ketone was synthesized. The synthesized compounds were characterized by elemental analysis and spectroscopic techniques. The first six homologues of the present series are non-mesogenic and mesomorphism appears from the heptyl derivative onwards. The present series shows a monotropic smectic A phase except for the last member (octadecyloxy) which exhibits an enantiotropic smectic A mesophase. The transition temperatures are also identified using DSC. The fluorescent studies of some of the compounds of the present series are under investigation.

New mesogenic compounds withtrans-stilbene oxide as the central chiral core

Abstract Several derivatives with the trans-stilbene oxide moiety as the central chiral core were synthesized. With the appropriate substituents, nematic and smectic C phases were observed. One derivative was obtained with an ee of 47 per cent by asymmetric synthesis. The chemical stability of these epoxides is low and they rearrange to give substituted phenyl benzylketones which are also liquid-crystalline. The structure of the two solid phases present in all the derivatives and of the smectic C phases was investigated by X-ray diffraction.

ChemInform Abstract: Reactions of Titanium Derivatives of Some CH‐Acids with Carbonyl Compounds. Part 2. Aldol Condensations with Titanium Derivatives of Benzyl Cyanide, Isopropyl Phenylacetate, Phenyl Benzyl Ketone and Ethyl Benzyl Ketone.

AbstractWhereas aliphatic aldehydes (II) and ketones with the titanium reagent (I) form the aldol adducts (III) and (IV) in approximately equal erythro/threo ratio, with aromatic and heterocyclic aldehydes (V), α‐alkylidenephenylacetonitriles (VI) are obtained.

ChemInform Abstract: A New Synthesis of 10,11‐Dihydrodibenz(b,f)oxepin‐10‐ones: Key Intermediates to Cularine Alkaloids.

AbstractCoupling of the benzylic halides (I) with the lithiated dithianes derived from (II) yields the benzyl phenyl ketone dithioacetals (III).

Effective synthesis of 7-hydroxyisoflavone O-glucosides

An effective procedure for condensing acetobromoglucose with 2,4-dihydroxy-phenyl benzyl ketones has been developed. The 2-hydroxy-4-(β-D-tetra-O-acetylglucopyranosyloxy)phenyl benzyl ketones synthesized with yields of 47–69% have been converted under the action of ethyl orthoformate in pyridine solution into 7-hydroxyisoflavone O-glucosides and these have also been obtained by the glycosylation of 7-hydroxyisoflavone. The advantages and disadvantages of the alternative pathways of the synthesis of 7-hydroxyisoflavone O-glycosides are discussed.

Asymmetric hydrogen transfer reactions from propan-2-ol to ketones catalyzed by Ir(I) derivatives with chiral schiff bases

Alkyl phenyl ketones are effectively reduced using propan-2-ol as hydrogen source and a series of Ir(I) complexes with chiral bidentate Schiff bases as catalysts. Both the activity and the selectivity strongly depend on the nature of the substituents at the chiral center of the ligand and at the prochiral center of the substrate. Optical yields of 50% (100% conversion) are obtained in the reduction of t-butyl phenyl ketone and benzyl phenyl ketone.

Thermal decomposition of benzyl phenyl ether and benzyl phenyl ketone in the presence of tetralin

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermal decomposition of benzyl phenyl ether and benzyl phenyl ketone in the presence of tetralinYoshiki Sato and Toshio YamakawaCite this: Ind. Eng. Chem. Fundamen. 1985, 24, 1, 12–15Publication Date (Print):February 1, 1985Publication History Published online1 May 2002Published inissue 1 February 1985https://doi.org/10.1021/i100017a003RIGHTS & PERMISSIONSArticle Views309Altmetric-Citations13LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (428 KB) Get e-Alerts