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.
Preparation method for pinaverium bromide intermediate 2-bromo-4,5-dimethoxybenzyl bromide
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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.
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.