Laser Desorption Ionization of Arylene Phenylphosphonites Formed by Condensation of Dihydric Phenols with Phenylphosphonous Bis(diethylamide)

Step high-temperature condensation of dihydric phenols [1,4-dihydroxybenzene, 4,4′-dihydroxybiphenyl, and 2,2′-bis(4-hydroxyphenyl)propane] with phenylphosphonous bis(diethylamide) is carried out. The molecular weight, composition, and structure of the resulting oligomeric arylene phenylphosphonites were assessed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The widest mass range was observed in the mass spectrum of 4,4′-dihydroxybiphenyl, which corresponds to an oligomer having about 30 elementary units. The obtained data agree with the the molecular weight measured by high-speed sedimentation. The reactions of phenylphosphonous bis(diethylamide) with dihydric phenols give both acyclic and cyclic arylene phenylphosphonites.     

双(烷基环戊二烯基)金属二卤和二芳氧基衍生物的研究

本文报导烷基环戊二烯基钠与金属氯化物反应合成钛、锆和铪的双(烷基环戊二烯基)金属二氯化物以及通过卤素交换制备双(烷基环戊二烯基)钛的二氟化物的方法。同时报导了以上的二氯化物与酚反应制备的一系列芳氧基金属衍生物。本文还讨论了金属、卤素、烷基对于质子化学位移的影响并探讨了主要红外吸收峰的归属。     

Bis(triarylmethylium)-mediated diaryl ether synthesis: oxidative arylation of phenols with N,N-dialkyl-4-phenylthioanilines

Various aryl 4-dialkylaminophenyl ethers were readily synthesized without heating in good yield from phenols and N,N-dialkyl-4-phenylthioanilines. This oxidative arylation of phenols was successfully promoted by a bis(diphenylmethylium)naphthalenediyl dication via ipso-substitution of the phenylthio group in the anilines through a radical process.     

Synthesis and properties of bowl‐shaped homotriazacalix[3 and 6] arenes and the acyclic analogues

Bowl‐shaped chiral homotriazacalixarenes were prepared by the cyclization reactions of chiral triamines with three equimolar amounts of bis(chloromethyl) phenols or bis(chloromethyl) phenol‐formaldehyde dimers in moderate yields. The corresponding acyclic phenol‐formaldehyde oligomers were also synthesized. The structural analysis of the macrocycles by nmr and circular dichroism spectra imply the existence of chiral transmission from the point chirality of the cysteine bridge to the cyclophane moiety. Their cyclic and acyclic compounds have a π‐base cavity large enough to include the ammonium ion.     

CuI/Oxalamide Catalyzed Couplings of (Hetero)aryl Chlorides and Phenols for Diaryl Ether Formation

Couplings between (hetero)aryl chlorides and phenols can be effectively promoted by CuI in combination with an N‐aryl‐N′‐alkyl‐substituted oxalamide ligand to proceed smoothly at 120 °C. For this process, N‐aryl‐N′‐alkyl‐substituted oxalamides are more effective ligands than bis(N‐aryl)‐substituted oxalamides. A wide range of electron‐rich and electron‐poor aryl and heteroaryl chlorides gave the corresponding coupling products in good yields. Satisfactory conversions were achieved with electron‐rich phenols as well as a limited range of electron‐poor phenols. Catalyst and ligand loadings as low as 1.5 mol % are sufficient for the scaled‐up variants of some of these reactions.     

Synthesis of 3-phenoxy-1,3-dihydro-1-isobenzofuranones by palladium-catalyzed carbonylative cyclization of 2-bromobenzaldehyde with phenols

2-Bromobenzaldehyde reacts with phenols in acetonitrile under carbon monoxide pressure in the presence of a catalytic amount of bis(triphenylphosphine)palladium(II) chloride to afford the corresponding 3-phenoxy-1,3-dihydro-1-isobenzofuranones in high yields.     

Synthesis of Polyfunctional Aromatic Ring Systems (Phloroglucide Analogs) under Microwave Irradiation

An efficient and rapid synthesis of phloroglucide analogs under microwave irradiation is described. The solid‐phase condensation reaction of the 4‐halo‐2,6‐bis(hydroxymethyl)phenols 1a , b with other substituted phenols in the presence of ZnCl₂ afforded the target molecules in much higher yields than by classical solution‐phase synthesis and allowed us to prepare new phloroglucide analogs possessing sensitive functional groups difficult to access by established means.     

Efficient Acetylation of Alcohols and Phenols Catalyzed by Recyclable Lithium Bis(perfluoroalkylsulfonyl)imide

An efficient acetylation of alcohols and phenols catalyzed by lithium bis(perfluoroalkylsulfonyl)-imide was developed. This acetylation features good yields, mild reaction condtions, and simple workup procedures. Furthermore, the catalyst bearing a long perfluoroalkyl chain is recoverable and readily reusable without losing any activity.     

Studies on the catalysis of the reaction of organotin phenoxides with bis(2,2,2‐trichloroethyl) azodicarboxylate by lithium perchlorate

Organotin phenoxides, which are distinctly more active than the corresponding phenols, react at room temperature with bis(2,2,2‐trichloroethyl) azodicarboxylate to produce para‐substituted phenolic hydrazides in high yields. Copyright © 2004 John Wiley & Sons, Ltd.     

Efficient oxidative ipso-fluorination of para-substituted phenols using pyridinium polyhydrogen fluoride in combination with hypervalent iodine(III) reagents

Diacetoxyiodobenzene (PIDA) and bis(trifluoroacetoxy)iodobenzene (PIFA) in the presence of pyridinium polyhydrogen fluoride (PPHF) are effective for the fluorination of para-substituted phenols to give a variety of 4-fluorocyclohexa-2,5-dienones in a good yield. (R,S)-1,1′-Bi-5,6,7,8-tetrahydro-2-naphthol (and its monoacetate) yields atropoisomeric fluorocyclohexadienones. The 4-substituted carbamate open-chain phenols were readily converted to fluorohydroindolenone and fluorohydroquinolenone derivatives by intramolecular conjugate addition.     

Monofluoromethyl‐Substituted Sulfonium Ylides: Electrophilic Monofluoromethylating Reagents with Broad Substrate Scopes

Two electrophilic monofluoromethylating reagents, monofluoromethyl(phenyl)sulfonium bis(carbomethoxy)methylide ( 3 a ) and monofluoromethyl(4‐nitrophenyl)sulfonium bis(carbomethoxy)methylide ( 3 b ), and their reactions under mild conditions with a variety of nucleophiles, such as alcohols and malonate derivatives, sulfonic and carboxylic acids, phenols, amides, and N heteroarenes, are described. Mechanistic studies with deuterated reagents [D₂] 3 a /[D₂] 3 b suggest that these monofluoromethylation reactions proceed through an electrophilic substitution pathway.     

Syntheses of symmetric and unsymmetric 2,6‐bis(phosphino)phenols

Compounds bearing the structural motif of 2,6‐bis(phosphino)phenol have been synthesized via two general methods. Double lithium‐halogen exchange occurred in low‐temperature reactions of O‐protected (by methyl‐ or tetrahydropyranyl groups) 2,6‐dibromo‐4‐methylphenol derivatives with BuLi (2 equivalents); quenching the reaction mixtures with chlorophosphines ClPR₂ (R = Ph, ⁱPr) and corresponding O‐deprotection yielded symmetrically substituted 2,6‐bis(phosphino)phenols. Sequential incorporation of  PR₂ functionalities was accomplished via single lithium‐halogen exchange (1 eq. of BuLi) of tetrahydropyranyl‐protected 2,6‐dibromo‐4‐methylphenol followed by ClPR₂ quenches, thus enabling the syntheses of unsymmetric 2,6‐bis(phosphino)phenols. Such compounds were also obtained via sequential ortho‐lithiations of tetrahydropyranyl‐protected 4‐tert‐but ylphenol, followed by ClPR₂ quenches. All of the new compounds have been characterized by spectrometric methods (¹H and ³¹P NMR, and mass spectrometry). In addition, two of the compounds, 1‐(diphenylphosphino)‐3‐(diphenylphosphoryl)‐2‐methoxy‐5‐methylbenzene ( 3a‐ox ) and 1,3‐bis(diphenylphosphino)‐2‐methoxy‐5‐methylbenzene ( 6a ) have also been characterized via single crystal X‐ray diffraction experiments. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:656–663, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20251     

Efficient ortho-oxidation of phenol and synthesis of anti-MRSA and anti-VRE compound abietaquinone methide from dehydroabietic acid

A quinone methide diterpene: abietaquinone methide, which possesses potent anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-vancomycin-resistant Enterococcus (VRE) activities, was synthesized via efficiently ortho-oxidation of ferruginol derived from industrially available dehydroabietic acid. ortho-Oxidation of phenols was developed to give mono esters of catechols using a stable diacyl peroxide, bis(4-chlorobenzoyl) peroxide (m-chlorobenzoyl peroxide: mCBPO) which was synthesized from meta-chlorobenzoic acid. Efficient one pot ortho-oxidation reaction of phenol with an adduct of meta-chloroperbenzoic acid (mCPBA) with dicyclohexylcarbodiimide (DCC) was also reported.     

Regioselective [3+3] Cyclization of 1,3‐Bis(silyloxy)buta‐1,3‐dienes with 1,1,1‐Trifluoro‐4‐(silyloxy)alk‐3‐en‐2‐ones: New and Convenient Synthesis of Functionalized 5‐Alkyl‐3‐(trifluoromethyl)phenols

Functionalized 5‐alkyl‐3‐(trifluoromethyl)phenols were prepared by formal [3+3] cyclization of 1,3‐bis(silyloxy)buta‐1,3‐dienes with 1,1,1‐trifluoro‐4‐(silyloxy)alk‐3‐en‐2‐ones derived from 1,1,1‐trifluoroalkane‐2,4‐diones. The latter were prepared by condensation of the dianion of 1,1,1‐trifluoropentane‐2,4‐dione with alkyl halides.     

Application of bis(iminophosphorane) in heterocyclic synthesis: new entries to symmetrically or unsymmetrically substituted thieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-diones

The bis(carbodiimides) 4, obtained from bis-aza-Wittig reactions of bis(iminophosphorane) 3 with 2 equiv of aromatic isocyanates, were reacted with secondary amine to give symmetrically substituted 2,7-diaminothieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-dione 6 in the presence of a catalytic amount of EtO(-)Na(+). Reactions of 4 with phenols or ROH in the presence of a catalytic amount of potassium carbonate or RO(-)Na(+) gave symmetrically substituted 2,7-diaryl(alkyl)oxythieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-diones 6 in satisfactory yields. However, iminophosphoranes 9 were obtained via reaction of bis(iminophosphorane) 3 with 1 equiv of aromatic isocyanate and subsequent reaction with an amine in the presence of a catalytic amount of EtO(-)Na(+). Further reaction of iminophosphoranes 9 with aromatic isocyanates and various nucleophile generated unsymmetrically substituted thieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-diones 12 in good yields.     

Glyoxal bis(phenylhydrazone) as promoter for CuI-catalyzed O-arylation of phenols with bromoarenes

A very simple bishydrazone-type ligand, glyoxal bis(phenylhydrazone) (L1), was found to effectively promote the CuI-catalyzed O-arylation of phenols with aryl bromides. This cross-coupling reaction proceeded in acetonitrile at 60-80 °C in the presence of K₃PO₄ as base. A diverse array of phenols and bromoarenes was employed as substrates to afford diaryl ethers in good to excellent yields, and some base-sensitive groups, such as ester, aldehyde, and ketone groups, can survive under the mild reaction conditions.     

Group 3 Metal Initiators with an [OSSO]‐Type Bis(phenolate) Ligand for the Stereoselective Polymerization of Lactide Monomers

A series of 1,ω‐dithiaalkanediyl‐bridged bis(phenols) of the general type [OSSO]H₂ with variable steric properties and various bridges were prepared. The stoichiometric reaction of the bis(phenols) 1,3‐dithiapropanediyl‐2,2′‐bis(4,6‐di‐tert‐butylphenol), 1,3‐dithiapropanediyl‐2,2′‐bis[4,6‐di(2‐phenyl‐2‐propyl)phenol], rac‐2,3‐trans‐propanediyl‐1,4‐dithiabutanediyl‐2,2′‐bis[4,6‐di(2‐phenyl‐2‐propyl)phenol], rac‐2,3‐trans‐butanediyl‐1,4‐dithiabutane diyl‐2,2′‐bis[4,6‐di(2‐phenyl‐2‐propyl)phenol], rac‐2,3‐trans‐hexanediyl‐1,4‐dithiabutanediyl‐2,2′‐bis[4,6‐di(2‐phenyl‐2‐propyl)phenol], 1,3‐dithiapropanediyl‐2,2′‐bis[6‐(1‐methylcyclohexyl)‐4‐methylphenol] (C₁, R=1‐methylcyclohexyl), and 1,4‐dithiabutanediyl‐2,2′‐bis[6‐(1‐methylcyclohexyl)‐4‐methylphenol] with rare‐earth metal silylamido precursors [Ln{N(SiHMe₂)₂}₃(thf)_x] (Ln=Sc, x=1 or Ln=Y, x=2; thf=tetrahydrofuran) afforded the corresponding scandium and yttrium bis(phenolate) silylamido complexes [Ln(OSSO){N(SiHMe₂)₂}(thf)] in moderate to good yields. The monomeric nature of these complexes was shown by an X‐ray diffraction study of one of the yttrium complexes. The complexes efficiently initiated the ring‐opening polymerization of rac‐ and meso‐lactide to give heterotactic‐biased poly(rac‐lactides) and highly syndiotactic poly(meso‐lactides). Variation of the ligand backbone and the steric properties of the ortho substituents affected the level of tacticity in the polylactides.     

Organic hybrid of chlorinated polyethylene and hindered phenol. II. Influence of the chemical structure of small molecules on viscoelastic properties

The viscoelastic properties and stabilities of those properties of organic hybrids consisting of chlorinated polyethylene (CPE) and tetrakis[methylene‐3‐(3‐5‐di‐tert‐butyl‐4‐hydroxy phenyl)propionyloxy]methane (AO‐60) and triethylene glycol bis[3‐(3‐tert‐butyl‐4‐hydroxy‐5‐methyl phenyl)propionyloxy] (AO‐70) were investigated. The CPE/AO‐70 hybrids show only one transition, whereas for the CPE/AO‐60 hybrids, one novel relaxation appears above the glass‐transition temperature of CPE. This relaxation on the higher temperature side in the mechanical spectrum for CPE/AO‐60 is associated with the appearance of the AO‐60‐rich phase. Furthermore, the stabilities of the viscoelastic properties and microstructures of the organic hybrids consisting of CPE and multifunctional hindered phenols are dominated by the strength of the intermolecular interaction between CPE and phenols and the conformations of the middle skeletal parts of hindered phenols. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1496–1503, 2000     

Bis(trifluoroacetyl)phenols and their derivatives in reactions with selected phosphorus(III) compounds

The reactivity of bis(trifluoroacetyl)‐phenols toward selected λ³P derivatives was examined. In the case of dialkyl(isocyanato)phosphites, only one of both present trifluoracetyl moieties of substrate was involved. After addition of the phenolic OH moiety across the intermediary formed PN bond, tri‐, tetra‐, and pentacyclic α‐(trifluoromethyl)phosphoranes were produced in a highly diastereoselective reaction. An unusual deoxygenation of the intermediary hydroxyphosphorane was observed reacting 4‐methyl‐2,6‐bis‐(trifluoroacetyl)phenol with diethyl(trimethylsilyl)‐phosphite, and the subsequent hydrolysis gave γ‐hydroxy‐α‐(trifluoromethyl)phoshonate. On the contrary, during the reaction of the O‐silylated phenol with tris(trimethylsilyl)phosphite, a bis‐phosphonate was obtained that underwent heterocyclization to phosphono phosphole system. The mechanistic aspects of the studied reactions, as well as structural features of the synthesized compounds are discussed, based on the multinuclear NMR spectroscopy and X‐ray single crystal investigation data. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:474–482, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20451     

Reactions of sterically hindered phenols with P2S5

The direction of the reaction of 2,6-disubstituted phenols with P₂S₅ leading to bis(hydroxyaryl)dithiophosphinic acids orO,O-bis(aryl) dithiophosphates is determined by the degree of shielding of the OH group. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1442–1444, July, 1998.