Palladium-Catalyzed 1-Methylene-2-propenylation Reactions of Aryl Bromides with 3,4-Alkadien-1-ols via Carbon-Carbon Bond Cleavage for the Synthesis of 2-Aryl-1,3-butadiene Derivatives
Palladium-Catalyzed 1-Methylene-2-propenylation Reactions of Aryl Bromides with 3,4-Alkadien-1-ols via Carbon-Carbon Bond Cleavage for the Synthesis of 2-Aryl-1,3-butadiene Derivatives
复制标题
DOI：
10.1246/bcsj.82.393
复制
发表时间：
2009-03-15
影响因子：
4
通讯作者：
Oshima, Koichiro
中科院分区：
文献类型：
--
作者：
Imoto, Junichi;Hayashi, Sayuri;Oshima, Koichiro
本文提出了一种合成2-芳基-1,3-烷烯的方法。在钯催化剂的存在下，用3,4-alkadien-1-ol处理芳基溴导致1-亚甲基-2-丙烯基团转移到芳基溴。利用钯介导的反烯丙基化反应作为sp(3)C-sp(3)C键裂解反应，可以将3,4-烷二烯-1-醇视为易于制备且对空气和水分不敏感的1-亚甲基-2-丙烯金属当量。如果在1-亚甲基-2-丙烯化反应中产物的Diels-Alder二聚化有问题，在反应混合物中加入n -甲基吡咯可以有效地抑制二聚化。芳基溴与2-取代3,4-烷二烯-1-醇反应立体选择性地生成相应的(E)-2-芳基1,3-烷二烯。
A method for the synthesis of 2-aryl-1,3-alkadienes has been developed. Treatment of aryl bromides with 3,4-alkadien-1-ols in the presence of a palladium catalyst results in 1-methylene-2-propenyl group transfer to aryl bromides. Taking advantage of palladium-mediated retro-allylation as an sp(3)C-sp(3)C bond cleavage reaction, one can regard 3,4-alkadien-1-ols as 1-methylene-2-propenyl metal equivalents that are easy to prepare and are not sensitive to air and moisture. In the event that the Diels-Alder dimerization of the product during the 1-methylene-2-propenylation reaction is problematic, addition of N-methylpyrrole to the reaction mixture can efficiently suppress the dimerization. The reactions of aryl bromides with 2-substituted 3,4-alkadien-1-ols yield the corresponding (E)-2-aryl-1,3-alkadienes stereoselectively.