نتایج جستجو برای: friedel
تعداد نتایج: 1232 فیلتر نتایج به سال:
The first enantioselective synthesis of the fungal metabolite (+)-O-methylasparvenone was achieved in eight steps and 22% overall yield from inexpensive 3,4,5-trimethoxybenzaldehyde dimethyl acetal. Key steps include (i) early-stage asymmetric alkynylation of an aromatic aldehyde with a propiolate, (ii) intramolecular Friedel-Crafts acylation, and (iii) site-selective cleavage of an aryl methyl...
The first asymmetric aza-Friedel-Crafts reaction of indoles and pyrroles with isatin-derived N-Boc ketimines catalyzed by chiral phosphoric acids is reported. In general, derivatives of substituted 3-amino-2-oxindoles were obtained with excellent enantioselectivities and high yields.
An iridium(I) catalyst system, modified with the wide-bite-angle and electron-deficient bisphosphine d(F) ppb (1,4-bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch-selective hydroarylation reactions between diverse acetanilides and aryl- or alkyl-substituted alkenes. This provides direct and ortho-selective access to synthetically challenging anilines, and addresses long-standi...
The synthetic route in this work is based on the classical Friedel-Crafts strategy, and began with 1,4-dimethoxybenzene (I), followed by alkylation and selective demethylation of 2-methoxy function in 0x0-acid (3). The orthoformylation to synthesize aldehyde (6) was based on the Reimer-Tieman reaction. Chain extension of this aldehyde required methylation of the hydroxyl group and condensat...
The synthesis of 1,5-dihydroxy-9,10-anthraquinone (17); (1,5-DHA) was accomplished during, attempts towards the synthesis one of its derivatives called anthralin (1,8-dihydroxy-9-anthrone) which is known as an antipsoriasis drug since 1916 [1]. This work is a new reigiospecilic preparation of 1,5-DHA based on Friedel-Crafts reaction starting from 1,4-dimethoxybenzene. This synthetic route, ...
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