- A simple Lewis acid induced reaction of phenols with electrophiles: Synthesis of functionalized 4H-chromenes and ortho-benzylphenols
-
Lewis acid ZnCl2 promoted cyclization protocol to 4H-chromenes is accomplished, using readily available phenols and acetophenones as starting materials. Interestingly, the process is feasible under the solvent free environment. Synthesis of a variety of 4H-chromenes have been accomplished using this strategy. In addition, this concept is extended to the synthesis of ortho-benzylphenols by treating phenols either with styrenes or secondary benzylic alcohols.
- Sreenivasulu, Chinnabattigalla,Thadathil, Ditto Abraham,Pal, Sumit,Gedu, Satyanarayana
-
p. 112 - 122
(2019/11/19)
-
- Hydroarylation of alkynes and alkenes through alumina-sulfuric acid catalyzed regioselective C–C bond formation
-
A highly atom-efficient synthetic protocol for hydroarylation of terminal-aryl alkynes and styrene through the regioselective C–C bond formation via the electrophilic addition of naphthols and substituted phenols has been developed using alumina-sulfuric acid as a heterogeneous supported solid acid catalyst. This methodology shows excellent regioselectivity and affords the desired product in good to excellent yield. The heterogeneous catalyst can also be recycled efficiently without much loss of activity.
- Pramanik, Amit,Ghatak, Avishek,Khan, Sagar,Bhar, Sanjay
-
supporting information
p. 1091 - 1095
(2019/03/26)
-
- HBF4- and AgBF4-Catalyzed ortho-Alkylation of Diarylamines and Phenols
-
A silver-tetrafluoroborate- or HBF4-catalyzed ortho-alkylation reaction of phenols and diarylamines with styrenes has been explored. A broad substrate scope is presented as well as mechanistic experiments and discussion.
- Rank, Christian K.,?zkaya, Bünyamin,Patureau, Frederic W.
-
supporting information
p. 6830 - 6834
(2019/09/12)
-
- Catalytic Tandem and One-Pot Dehydrogenation-Alkylation and -Insertion Reactions of Saturated Hydrocarbons with Alcohols and Alkenes
-
The ruthenium-hydride catalyst has been successfully used for the tandem sp3 C-H dehydrogenation-alkylation reaction of saturated hydrocarbon substrates with alcohols to form the alkyl-substituted alkene and arene products. The analogous one-pot dehydrogenation-insertion of saturated ketones with alkenes and dienes directly yielded synthetically useful 2-alkylphenol and benzopyran products in a highly regio- and stereoselective manner without forming any wasteful byproducts. (Chemical Equation Presented).
- Kim, Junghwa,Pannilawithana, Nuwan,Yi, Chae S.
-
p. 8395 - 8398
(2016/12/16)
-
- Microwave assisted benzylation of naphthols and 4-hydroxycoumarin under catalyst & solvent free conditions
-
An expeditious and highly practical, microwave assisted benzylation of naphthols and 4-hydroxycoumarin has been developed under catalyst-free & solvent-free conditions. Alcohols undergo heat induced dehydration to form ethers, which collapse reversibly to form the carbocation which was captured immediately by a suitable nucleophile to furnish the benzylated compounds.
- Dada, Ravikrishna,Singh, Garima,Pareek, Abhishek,Kausar, Saeen,Yaragorla, Srinivasarao
-
p. 3739 - 3742
(2016/07/26)
-
- FT-IR, 1H NMR, 13C NMR and X-ray crystallographic structure determination of 4-nitro-benzenesulfonic acid 2,4-bis-(1-phenyl-ethyl)-naphthalen-1-yl ester
-
The title compound C32H27NO5S belongs to the monoclinic system, space group P21/c with a = 14.4530(5) ?, b = 13.9185(5) ?, c = 13.5714(4) ?, α = γ = 90°, β = 87.174(3), V = 2726.76(16) ?3, Z = 4, D c = 1.310 g/cm3, F(000) = 1128, R = 0.053 and wR = 0.133, S = 1.03, T = 296 K. In the title compound, the naphthalene unit is planar (r.m.s. deviation = 0.0227 ?). The dihedral angle between the naphthalene unit and nitro-benzenesulfonic acid, 2-phenyl-ethyl and 4-phenyl-ethyl are 49.68(05)°, 82.96(06)°, and 81.94(07)°respectively. The structure is stabilized by intra- and intermolecular C-H...O hydrogen bonds.
- Kayalvizhi,Vasuki,Veerareddy,Sreenivasulureddy,Veerabhadrarao
-
p. 392 - 395
(2015/06/08)
-
- Dehydrative C-H alkylation and alkenylation of phenols with alcohols: Expedient synthesis for substituted phenols and benzofurans
-
A well-defined cationic Ru-H complex catalyzes the dehydrative C-H alkylation reaction of phenols with alcohols to form ortho-substituted phenol products. Benzofuran derivatives are efficiently synthesized from the dehydrative C-H alkenylation and annulation reaction of phenols with 1,2-diols. The catalytic C-H coupling method employs cheaply available phenols and alcohols, exhibits a broad substrate scope, tolerates carbonyl and amine functional groups, and liberates water as the only byproduct.
- Lee, Dong-Hwan,Kwon, Ki-Hyeok,Yi, Chae S.
-
scheme or table
p. 7325 - 7328
(2012/06/16)
-
- 3D Nanoporous FeAl-KIT-5 with a cage type pore structure: A highly efficient and stable catalyst for hydroarylation of styrene and arylacetylenes
-
A novel bimetallic nanoporous FeAl-KIT-5 catalyst with a cage type porous structure and a high surface area has been prepared for the hydroarylation of styrene and arylacetylenes to afford 1,1-diarylalkanes and 1,1-diarylalkenes, respectively. The catalyst was found to be highly active, and selective, affording a high yield of substituted alkanes and alkenes. The catalyst also showed much higher activity as compared to those of other nanoporous catalysts such as AlSBA-15, AlKIT-5, and FeKIT-5, and can be reused several times without much loss of its activity.
- Varghese, Shaji,Nagarajan, Samuthira,Benzigar, Mercy R.,Mano, Ajayan,Alothman, Zeid A.,Raj, George Allen Gnana,Vinu, Ajayan
-
experimental part
p. 1485 - 1489
(2012/03/27)
-
- H-β-zeolite-catalysed hydroarylation of styrenes
-
The hydroarylation of styrenes with various arene(heteroarene) compounds using H-β-zeolite as a green and recyclable heterogeneous catalyst under mild reaction conditions has been developed. The catalyst showed versatility and high selectivity (up to 100a€‰%) of desired 1,1-diarylalkanes in cyclohexane as solvent under the conditions studied. The catalyst could be reactivated by simple treatment with mineral acid at room temperature for better catalytic activity. Hydroarylation of styrenes with variousarene(heteroarene) compounds using H-β-zeolite as a green, heterogeneous and reusable catalyst under mild conditions is reported.
- Mohan, Darapaneni Chandra,Patil, Rajendra D.,Adimurthy, Subbarayappa
-
experimental part
p. 3520 - 3525
(2012/07/30)
-
- KHSO4: A highly efficient and reusable heterogeneous catalyst for hydroarylation of styrenes
-
Hydroarylation of styrenes with arenes/heteroarenes using KHSO4 (10 mol%) as an efficient heterogeneous catalyst is described. High conversion and selectivity (>99%) were observed for hydroarylation of styrenes with 2-naphthol at reflux temperature of 1,2-dichloroethane. Yields were quantitative with all styrenes. Moderate to good conversions and selectivities were achieved with other aromatics and heteroaromatics under the same conditions. Regeneration and reusability of KHSO4 were demonstrated. Addition of a trace amount of water could help to reactivate the KHSO4 through dispersion and to facilitate the hydroarylation reaction. Springer-Verlag 2010.
- Patil, Rajendra D.,Joshi, Girdhar,Adimurthy, Subbarayappa
-
experimental part
p. 1093 - 1099
(2012/07/16)
-
- Simple and efficient metal-free hydroarylation and hydroalkylation using strongly acidic ion-exchange resin
-
Higly efficient hydroarylation and hydroalkylation of styrenes with various arenes and 1,3-dicarbonyl compounds respectively have been developed using Amberlyst-15 as a heterogeneous catalyst. The excellent yields, short reaction times, and high selectivity are the advantages of this method. The C-H functionalization has been achieved here under metal-free conditions. Copyright
- Das, Biswanath,Krishnaiah, Martha,Laxminarayana, Keetha,Damodar, Kongara,Kumar, D. Nandan
-
experimental part
p. 42 - 43
(2009/12/02)
-
- Gallium(III) chloride catalyzed hydroarylation of arylacetylenes with naphthols and phenols: A facile synthesis of vinylarenes
-
Arylacetylenes undergo smooth hydroarylation with naphthols and phenols in the presence of 10 mol% of gallium(III) chloride in refluxing toluene to afford the corresponding 2-vinylnaphthols and -phenols in good yields with high regioselectivity. Similarly, styrenes undergo hydroarylation with naphthols and phenols to provide substituted naphthols and phenols. Georg Thieme Verlag Stuttgart.
- Yadav, Jhillu S.,Subba Reddy, Basi V.,Sengupta, Sandip,Biswas, Swapan Kumar
-
experimental part
p. 1301 - 1304
(2009/12/07)
-
- Benzylation and allylation of naphthols using amberlyst-15
-
A simple and efficient method has been developed for benzylation and allylation of naphthols by treatment of the compounds with benzylic and allylic alcohols, respectively, in the presence of amberlyst-15. Several heterogeneous catalysts were screened for
- Das, Biswanath,Veeranjaneyulu, Boyapati,Krishnaiah, Maddeboina,Balasubramanyam
-
experimental part
p. 1929 - 1935
(2009/10/17)
-
- Cyclodextrin-mediated regioselective photo-Fries reaction of 1-naphthyl phenyl acylates
-
1-Naphthyl phenyl acylates upon irradiation in solution yield eight products via β-cleavage process. However, excitation of these molecules as included in γ-cyclodextrin results in a single product (>95%). This medium dependent product selectivity is attributed to conformational and translational restrictions enforced on the reactant as well as intermediates by the cyclodextrin cavity.
- Koodanjeri, Smriti,Pradhan, Ajit R.,Kaanumalle, Lakshmi S.,Ramamurthy
-
p. 3207 - 3210
(2007/10/03)
-
- Alkali metal ion controlled product selectivity during photorearrangements of 1-naphthyl phenyl acylates and dibenzyl ketones within zeolites
-
Photochemical behaviors of 1-naphthyl phenyl acylates and dibenzyl ketones included in zeolites have been compared. 1-Naphthyl phenyl acylates while in solution produce eight photoproducts; within NaY it gives a single product. The selectivity is attributed to the restriction brought on the mobility of the primary radical pair by the alkali metal ions present in zeolites. Photochemistry of dibenzyl ketones within NaY reveals that the intersystem crossing in caged radical pairs could be influenced by the heavy alkali metal ions. Structures of complexes among Li+ ion and the guest 1-naphthyl phenyl acetates and dibenzyl ketone computed at the B3LYP level have been useful to understand the origin of the observed product selectivity within zeolites.
- Warrier,Kaanumalle, Lakshmi S.,Ramamurthy
-
p. 620 - 631
(2007/10/03)
-
- Mediation of photochemical reactions of 1-naphthyl phenylacylates by polyolefin films. A 'radical clock' to measure rates of radical-pair cage recombinations in 'viscous space'
-
The fates of phenylacyl/1-naphthoxy singlet radical pairs generated upon irradiation of 1-naphthyl phenylacetate (1a) and 1-naphthyl 2-phenylpropanoate (1b) in three unstretched and stretched polyethylene films and isotactic and syndiotactic polypropylene films have been investigated. From dynamic fluorescence measurements the primary locus of reactions by 1 is within amorphous regions of the films. The reaction cages afforded by these media inhibit escape of the radical pairs and mediate their reorientational motions leading to photo-Fries and related products. In essence, the cages act as stiff-walled templates. In addition, a method is described to measure the rate constants for the singlet radical pairs. Thus, the rate constants (leading to the keto precursors) of the 2-phenylacyl-1-naphthols from the radical pairs of 1 (> 108 s-1) are >6 times the rate constants for the 4-isomers. Film stretching increases this selectivity but there is no obvious correlation between the rate of the in-cage radical pair recombinations and macroscopic polymer, properties such as degree of crystallinity and frequency of branched chains. By contrast, formation of (the keto precursors of) 2-benzylic-1-naphthols (from in-cage recombinations after phenylacyl decarbonylation) is slower than for the 4-benzyl-1-naphthols. (C) 2000 Elsevier Science Ltd.
- Gu, Weiqiang,Weiss, Richard G.
-
p. 6913 - 6925
(2007/10/03)
-
- 2-Substituted-1-naphthols as potent 5-lipoxygenase inhibitors with topical antiinflammatory activity
-
The synthesis, biological evaluation, and structure-activity relationships of a series of 1-naphthols bearing carbon substituents at the 2-position are described. These compounds are potent inhibitors of the 5-lipoxygenase from RBL-1 cells and also inhibi
- Batt,Maynard,Petraitis,Shaw,Galbraith,Harris
-
p. 360 - 370
(2007/10/02)
-