53207-00-4Relevant articles and documents
Pd-catalyzed sp-sp3cross-coupling of benzyl bromides using lithium acetylides
Buter, Jeffrey,Doze, Anna M.,Feringa, Ben L.,Mondal, Anirban,Visser, Paco
supporting information, p. 7529 - 7532 (2021/08/05)
Organolithium-based cross-coupling reactions have emerged as an indispensable method to construct C-C bonds. These transformations have proven particularly useful for the direct and fast coupling of various organolithium reagents (sp, sp2, and sp3) with aromatic (pseudo) halides (sp2). Here we present an efficient method for the cross-coupling of benzyl bromides (sp3) with lithium acetylides (sp). The reaction proceeds within 10 min at room temperature and can be performed in the presence of organolithium-sensitive functional groups such as esters, nitriles, amides and boronic esters. The potential application of the methodology is demonstrated in the preparation of key intermediates used in pharmaceuticals, chemical biology and natural products.
Formal total synthesis of salvianolic acid N
Wu, Kong,Xie, Zhong Pao,Cui, Dong-Mei,Zhang, Chen
, p. 832 - 837 (2018/02/09)
An efficient synthetic pathway for the total synthesis of salvianolic acid N has been reported. The key reaction steps, the Wittig reaction for Z-stereoselectivity and an intramolecular cyclization for a seven membered ring skeleton, have been optimized to improve the synthetic feasibility and provide the best conditions in terms of yield. Moreover, a notable reaction is the reaction of the deprotected allylic group with Pd catalyst. An improved overall yield of 11% has been achieved for salvianolic acid N starting from 3,4-dimethoxybenzaldehyde in 11 steps.
Preparation method for pinaverium bromide intermediate 2-bromo-4,5-dimethoxybenzyl bromide
-
Paragraph 0052; 0053; 0054; 0055; 0056; 0057; 0058-0071, (2018/03/01)
The invention provides a preparation method for a pinaverium bromide intermediate 2-bromo-4,5-dimethoxybenzyl bromide. The method comprises the following steps: in a nonpolar solvent, bromine released by a redox reaction of a bromate and a bromide under a sulfuric acid effect is used as a bromine source, the bromine and 3,4-dimethoxymethylbenzene represented by a formula (1) are subjected to an aromatic ring C-H bond electrophilic bromination reaction, after the reaction is fully completed, an initiator and sulfuric acid are added, a benzylic methyl C-H bond free radical bromination reaction is performed, and therefore the 2-bromo-4,5-dimethoxybenzyl bromide represented by a formula (8) is obtained, wherein the reaction equation is shown in the description. According to the invention, a one-pot method is adopted, the raw materials are cheap and easy to obtain, operation is simple, convenient and safe, production costs are reduced, the yield of the 2-bromo-4,5-dimethoxybenzyl bromide represented by the formula (8) is remarkably improved, wherein the yield is up to 85%, and the preparation method is very suitable for industrialized production.
Synthetic Utility of Arylmethylsulfones: Annulative π-Extension of Aromatics and Hetero-aromatics Involving Pd(0)-Catalyzed Heck Coupling Reactions
Sankar, Elumalai,Raju, Potharaju,Karunakaran, Jayachandran,Mohanakrishnan, Arasambattu K.
, p. 13583 - 13593 (2017/12/26)
A straightforward and general method for the synthesis of annulated thiophene, dibenzothiophene, and carbazoles analogues has been achieved involving alkylation of 2-bromo-1-(phenylsulfonylmethyl)arene/heteroarene with arylmethyl bromides/heteroarylmethyl bromides using t-BuOK as a base in DMF, followed by Pd(0)-mediated intramolecular Heck coupling in the presence of K2CO3 in DMF at 80-140 °C. The attractive feature of this protocol is that a wide variety of π-conjugated heterocycles could be readily accessed by an appropriate choice of arylmethylsulfones and benzylic bromides.
Hydrazone-palladium catalyzed annulation of 1-allyl-2-bromobenzene derivatives with internal alkynes
Watanabe, Kohei,Mino, Takashi,Hatta, Chikako,Ito, Shisei,Sakamoto, Masami
, p. 11645 - 11650 (2015/12/08)
Annulation of 1-allyl-2-bromobenzene derivatives with internal alkynes using a hydrazone-palladium catalyst system proceeded smoothly and gave the corresponding polysubstituted naphthalene derivatives in good to high yields.
CuI-catalyzed coupling of gem-dibromovinylanilides and sulfonamides: An efficient method for the synthesis of 2-amidoindoles and indolo[1,2-a] quinazolines
Kiruthika, Selvarangam E.,Perumal, Paramasivan Thirumalai
supporting information, p. 484 - 487 (2014/04/03)
A Cu(I)-catalyzed, intermolecular protocol for the synthesis of 2-amidoindoles and tetrahydroindolo[1,2-a]quinazolines in shorter time and high yields is reported. The key highlight of this disclosure is the formation of 2-amidoindole and tetrahydroindolo[1,2-a]quinazoline moieties directly from gem-dibromovinylanilides and sulfonamides in a one-pot fashion through the in situ formation of ynamides followed by a base-promoted intramolecular hydroamidation.
PROCESS FOR THE SYNTHESIS OF 3-(2-BROMO-4,5-DIMETHOXYPHENYL)PROPANENITRILE, AND APPLICATION IN THE SYNTHESIS OF IVABRADINE AND ADDITION SALTS THEREOF WITH A PHARMACEUTICALLY ACCEPTABLE ACID
-
Paragraph 0028-0030, (2014/06/24)
Process for the synthesis of the compound of formula (I): Application in the synthesis of ivabradine, addition salts thereof with a pharmaceutically acceptable acid and hydrates thereof.
Direct oxidative conversion of methylarenes into aromatic nitriles
Tsuchiya, Daisuke,Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
supporting information, p. 4194 - 4197 (2013/09/12)
A variety of methylarenes were successfully converted into the corresponding aromatic nitriles in good to moderate yields by the treatment with NBS or DBDMH in the presence of a catalytic amount of AIBN or BPO, followed by the reaction with molecular iodine in aq NH3 in a one-pot procedure. The present reaction is a useful and practical transition-metal-free method for the preparation of aromatic nitriles from methylarenes.
Intramolecular direct dehydrohalide coupling promoted by KOtBu: Total synthesis of amaryllidaceae alkaloids anhydrolycorinone and oxoassoanine
De, Subhadip,Ghosh, Santanu,Bhunia, Subhajit,Sheikh, Javeed Ahmad,Bisai, Alakesh
supporting information, p. 4466 - 4469 (2012/10/29)
A transition-metal-free intramolecular dehydrohalide coupling via intramolecular homolytic aromatic substitution (HAS) with aryl radicals has been developed in the presence of potassium tert-butoxide and an organic molecule as the catalyst. The methodology has been applied to a concise synthesis of Amaryllidaceae alkaloids viz. oxoassoanine (1b), anhydrolycorinone (1d), and other related structures. Interestingly, the method also works only in the presence of potassium tert-butoxide.
Synthesis and in vitro antibacterial activity of gemifloxacin derivatives containing a substituted benzyloxime moiety
Feng, Lianshun,Lv, Kai,Liu, Mingliang,Wang, Shuo,Zhao, Jing,You, Xuefu,Li, Sujie,Cao, Jue,Guo, Huiyuan
, p. 125 - 136 (2012/11/07)
A series of novel gemifloxacin (GMFX) derivatives containing a substituted benzyloxime moiety with remarkable improvement in lipophilicity were synthesized. The target compounds evaluated for their in vitro antibacterial activity against representative strains. Our results reveal that most of the target compounds have considerable potency against all of the tested Gram-positive strains including MRSA and MRSE (MIC: 90: 1 μg/mL) is 8-fold more active than GMFX, and 2-fold more active than GMFX and moxifloxacin against MRSE clinical isolates (MIC90: 4 μg/mL). Crown Copyright
