13429-10-2Relevant academic research and scientific papers
Ruthenium(II)-Catalyzed Regioselective C-8 Hydroxylation of 1,2,3,4-Tetrahydroquinolines
Chen, Changjun,Pan, Yixiao,Zhao, Haoqiang,Xu, Xin,Luo, Zhenli,Cao, Lei,Xi, Siqi,Li, Huanrong,Xu, Lijin
supporting information, p. 6799 - 6803 (2018/11/21)
Ru(II)-catalyzed chelation-assisted highly regioselective C8-hydroxylation of 1,2,3,4-tretrahydroquinolines has been developed. Various 1,2,3,4-tetrahydroquinolines underwent smooth C8-H hydroxylation with cheap and safe K2S2O8 as the oxidant and oxygen source to furnish the corresponding products in good to excellent yields with high tolerance of the functional groups. The choice of a readily installable and removable N-pyrimidyl directing group is the key to catalysis. Mechanistic studies suggest the involvement of a six-membered ruthenacycle intermediate in the catalytic cycle. The method can also be extended to the direct hydroxylation of other (hetero)arene C-H bonds.
Cp?Rh(III)/Bicyclic Olefin Cocatalyzed C-H Bond Amidation by Intramolecular Amide Transfer
Wang, Xiaoming,Gensch, Tobias,Lerchen, Andreas,Daniliuc, Constantin G.,Glorius, Frank
, p. 6506 - 6512 (2017/05/17)
A bicyclic olefin was discovered as a cocatalyst in a Cp?Rh(III)-catalyzed C-H bond amidation proceeding by an intramolecular amide transfer in N-phenoxyacetamide derivatives. Combining experimental and theoretical studies, we propose that the olefin promotes a Rh(III) intermediate to undergo oxidative addition into the O-N bond to form a Rh(V) nitrenoid species and subsequently direct the nitrenoid to add to the ortho position. The amide directing group plays a dual role as a cleavable coordinating moiety as well as an essential coupling partner for the C-H amidation. This methodology was successfully applied to the late-stage diversification of natural products and a marketed drug under mild conditions.
Palladium catalyzed Csp2-H activation for direct aryl hydroxylation: The unprecedented role of 1,4-dioxane as a source of hydroxyl radicals
Seth, Kapileswar,Nautiyal, Manesh,Purohit, Priyank,Parikh, Naisargee,Chakraborti, Asit K.
supporting information, p. 191 - 194 (2015/01/09)
A novel strategy for direct aryl hydroxylation via Pd-catalysed Csp2-H activation through an unprecedented hydroxyl radical transfer from 1,4-dioxane, used as a solvent, is reported with bio relevant and sterically hindered heterocycles and various acyclic functionalities as versatile directing groups.
Divergent reactivities of o-haloanilides with CuO nanoparticles in water: A green synthesis of benzoxazoles and o-hydroxyanilides
Khatun, Nilufa,Guin, Srimanta,Rout, Saroj Kumar,Patel, Bhisma K.
, p. 10770 - 10778 (2014/03/21)
In the present study, three divergent reaction paths emerged when o-haloanilides were subjected to CuO nanoparticles in water. o-Halo (I, Br) phenylbenzamides in the presence of CuO nanoparticles and Cs2CO 3 in water at 100 °C provided o-hydroxyphenyl benzamides as the major product. However, a complete change in selectivity was observed in the presence of an organic base/ligand (TMEDA), giving 2-arylbenzoxazole as the exclusive product. The above selectivities were not clearly distinct when the corresponding alkylamides were treated either in the presence or absence of the ligand. A number of o-halophenyl alkylamides provided either exclusively o-dehalogenated products or a mixture of o-dehalogenated and o-hydroxylated products, but none gave 2-alkylbenzoxazoles. In addition to the above selectivities, the use of an environmentally friendly solvent (water) and base, and the recyclability of the catalyst make this procedure a benign alternative to the existing methods for the synthesis of these molecules, viz. o-hydroxybenzamides and o-arylbenzoxazoles.
Composition for oxidation dyeing of keratin fibres and dyeing processes using these compositions
-
, (2008/06/13)
Compositions for oxidation dyeing of keratin fibers, and in particular of human keratin fibers such as the hair, comprising, in a medium which is suitable for dyeing, at least one heterocyclic oxidation base chosen from pyrazoles, certain pyrimidines, pyrazolopyrimidines and the acid addition salts thereof, and at least one coupler chosen from 2-substituted 5-aminoalkylphenol derivatives and the acid addition salts thereof, as well as dyeing processes using these compositions.
Composition for oxidation dyeing of keratin fibers and dyeing processes using these compositions
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, (2008/06/13)
Compositions for oxidation dyeing of keratin fibers, and in particular of human keratin fibers such as the hair, comprising, in a medium which is suitable for dyeing, (i) at least one oxidation base, (ii) at least one coupler chosen from 2-substituted 5-aminoalkylphenol derivatives and the acid addition salts thereof, and (iii) at least one additional coupler chosen from meta-phenylenediamines, meta-aminophenols, meta-diphenols, heterocyclic couplers and the acid addition salts thereof, as well as dyeing processes using these compositions.
Keratinous fiber dye composition containing a 2-substituted amino-5-alkylphenol derivative coupler
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, (2008/06/13)
A keratinous fiber dye composition comprising a developer and a coupler, wherein the coupler is a 2-substituted amino-5-alkylphenol derivative represented by the following formula (1): STR1 wherein the all symbols are defined in the disclosure, is disclosed. The keratinous fiber dye composition imparts a color tone of a high chroma and is excellent in coloring power and fastness.
2-STYRYLBENZOXAZOLE DERIVATIVES
Arient, Josef
, p. 3160 - 3165 (2007/10/02)
A series of 35 derivatives of 2-styrylbenzoxazole I-XXXV with methyl, chloro, hydroxy, methoxy, dimethylamino, nitro, cyano and methoxycarbonyl substituents have been prepared by reaction of substituted 2-acetamidophenol with respective benzaldehyde derivatives.
