101-53-1Relevant articles and documents
Alkylation on graphite in the absence of Lewis acids
Sereda, Grigoriy A.
, p. 7265 - 7267 (2004)
Graphite is introduced as a convenient catalyst for alkylation of aromatic compounds and alcohols by benzyl, tertiary alkyl, and secondary alkyl halides in the absence of strong Lewis acids. Primary alkyl halides are not active under the reaction conditions.
A New Ruthenium Catalysed Reaction. Benzylation of Functional Aromatic Compounds
Jaouhari, Rabih
, p. 1781 - 1784 (1994)
Ruthenium (II) and (III) complexes catalysed of the benzylation of functional aromatic compounds were described.Phenol, benzene and their derivatives were benzylated at 140-160 deg C, using a benzylhalide in non polar solvent or without it.
Divalent transition metal ion-exchanged faujasites as mild, efficient, heterogeneous Friedel-Crafts benzylation catalysts
Kumarraja,Pitchumani
, p. 105 - 111 (2003)
Ni2+-, Cu2+-, and Zn2+-exchanged faujasite (MY) zeolites efficiently catalyze the Friedel-Crafts benzylation of arenes in a clean and simpler method.
Extremely efficient cross-coupling of benzylic halides with aryltitanium tris(isopropoxide) catalyzed by low loadings of a simple palladium(II) acctate/Tris(p-tolyl)phosphine system
Chen, Chi-Ren,Zhou, Shuangliu,Biradar, Deepak Baburao,Gau, Han-Mou
, p. 1718 - 1727 (2010)
Highly efficient coupling reactions of benzylic bromides or chlorides with aryltitanium tris(isopropoxide) [ArTi(O-i-Pr)3] catalyzed by a simple palladium(II) Acctate/tris(p-tolyl)phosphine [Pd(OAc)2/ P(p-tolyl)3] system are reported. The coupling reactions proceed in general at room temperature employing low catalyst loadings of 0.02 to 0.2 mol%, affording coupling products in excellent yields of up to 99%. For benzylic bromides bearing strong electronwithdrawing cyano (CN) or trifluoromethyl (CF 3) substituents, the reactions require a higher catalyst loading of 1 mol%, or the reactions are carried out at 60°C. The catalytic system also tolerates (1-bromoethyl)benzene bearing β-hydrogen atoms while using a catalyst loading of 1 mol% to afford the coupling product in a 70% yield.
Direct electrosynthesis of ketones from benzylic methylenes by electrooxidative C-H activation
Meng, Li,Su, Jihu,Zha, Zhenggen,Zhang, Li,Zhang, Zhenlei,Wang, Zhiyong
, p. 5542 - 5545 (2013)
Electrify your chemistry! Direct electrosynthesis of ketones from benzylic methylenes in an undivided cell was realized in moderate to good yields (see scheme). In this electrosynthesis, electrons instead of conventional oxidants and catalysts are employed to make the reaction environmentally benign. Moreover, the reaction intermediate radical was detected by ESR spectroscopy and the reaction mechanism was clarified.
Mesoporous zirconium phosphate catalyzed reactions: Synthesis of industrially important chemicals in solvent-free conditions
Sinhamahapatra, Apurba,Sutradhar, Narottam,Roy, Biplab,Tarafdar, Abhijit,Bajaj, Hari C.,Panda, Asit Baran
, p. 22 - 30 (2010)
Mesoporous zirconium phosphate (m-ZrP) having high specific surface area and narrow pore size distributions is synthesized in basic medium using zirconium carbonate as source of zirconium. The concentration of phosphate in precursor solutions, as well as the calcination temperature, is found to influence the textural properties and acidity of synthesized m-ZrP significantly. Microscopic analysis indicates the presence of worm like pores with spherical morphology. The porous structure has remarkable thermal stability (up to 800 °C). DRIFT and NH3-TPD analysis suggest the presence of reasonable amount of Lewis and Bro?nsted acid sites. High catalytic activity of synthesized m-ZrP is observed towards Friedel-Craft (F.C.) benzylation reaction. The effect of acid strength of catalyst, reaction time, temperature and amount of catalyst towards Friedel-Craft benzylation reaction are also studied. The m-ZrP is highly active towards other acid catalyzed reactions in solvent-free conditions. The catalytic activity of m-ZrP is much higher than that of conventional layered ZrP. The catalysts were separated easily from reaction mixture, regenerated after a simple activation step and reused at least six times without significant loss in catalytic activity.
Rapid identification of cytochrome P450cam variants by in vivo screening of active site libraries
Speight, Robert E.,Hancock, Fred E.,Winkel, Chris,Bevinakatti, Hanamanthsa S.,Sarkar, Manish,Flitsch, Sabine L.,Turner, Nicholas J.
, p. 2829 - 2831 (2004)
The selection of cytochrome P450 enzymes from large variant libraries, and the subsequent use of these enzymes in preparative scale biotransformations, remains a formidable challenge due to the complexities of the associated electron transport systems. Here, a powerful approach for the generation and screening of P450cam libraries for new function is presented that is both flexible and robust. A targeted library was generated wherein only the P450cam active-site amino acids Y96 and F98 were fully randomized and biotransformations, using a novel P450cam whole-cell system, were screened by GC-MS for the hydroxylation of diphenylmethane. One in 50 of the reactions screened, including 16 different variants, produced 4-hydroxydiphenylmethane with up to 92% conversion observed in the case of the Y96A variant. These results demonstrate a primary example of the screening of P450cam libraries in a format that is compatible with extension to preparative scale reactions.
Zirconia-modified superacid UDCaT-5: An efficient and versatile catalyst for alkylation reactions under solvent-free conditions
Yadav, Ganapati D.,Pathre, Ganesh S.
, p. 2684 - 2691 (2008)
UDCaT-5, a modified version of zirconia, efficiently catalyzes alkylation of phenols with alcohols under environmentally safe, heterogeneous reaction conditions with high selectivity and in excellent yields. The high content present in UDCaT-5 with preservation of tetragonal phase of zirconia was responsible for the superactivity. Several phenolic compounds carrying either electron-sulfer releasing or electron-withdrawing substituents in the ortho, meta, and para positions afforded high yields of the products. Copyright Taylor & Francis Group, LLC.
12-Tungstophosphoric acid/zirconia - A highly active stable solid acid - Comparison with a tungstated zirconia catalyst
Devassy, Biju M.,Halligudi,Hegde,Halgeri,Lefebvre
, p. 1074 - 1075 (2002)
A highly active and stable zirconia supported 12-tung-stophosphoric acid catalyst is found to be 2-3 times more active in benzylation and acylation reactions than a tungstated zirconia catalyst.
Synthesis and catalytic reactivity of mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes
Ma, Zhi-Hong,Lv, Lin-Qian,Wang, Hong,Han, Zhan-Gang,Zheng, Xue-Zhong,Lin, Jin
, p. 225 - 233 (2016)
The reactions of five dinuclear carbonyl complexes [(η 5-C5Me4R)Mo(CO)3]2 [R = allyl, n Bu, t Bu, Ph, Bz] with I2 in chloroform solution gave the corresponding mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes [(η 5-C5Me4R)MoI(CO)3] [R = allyl (1), n Bu (2), t Bu (3), Ph (4), Bz (5)]. The molecular structures of complexes 2, 3 and 5 were determined by X-ray diffraction analysis. The results show that the substituent in the ring can directly affect the Mo-I bond distances; the more sterically hindered the substituent, the longer the Mo-I bond. Friedel-Crafts reactions of aromatic compounds with a variety of alkylation reagents catalyzed by the complexes showed that all of these mononuclear molybdenum carbonyl complexes have catalytic activity in Friedel-Crafts alkylation reactions. Indeed, compared with traditional catalysts, these mononuclear metal carbonyl complexes have obvious advantages such as higher activities, mild reaction conditions, high selectivity, simple post-processing, and environmentally friendly chemistry.
