A simple and mild synthesis of 1H-isochromenes and (Z)-1-alkylidene-1,3-dihydroisobenzofurans by the iodocyclization of 2-(1-alkynyl)benzylic alcohols.
A simple and mild synthesis of 1H-isochromenes and (Z)-1-alkylidene-1,3-dihydroisobenzofurans by the iodocyclization of 2-(1-alkynyl)benzylic alcohols.
复制标题
DOI：
10.1021/jo902333y
复制
发表时间：
2010-02-05
影响因子：
3.6
通讯作者：
Larock, Richard C.
中科院分区：
文献类型：
--
作者：
Mancuso, Raffaella;Mehta, Saurabh;Gabriele, Bartolo;Salerno, Giuseppe;Jenks, Williani S.;Larock, Richard C.
通过易得的2-（1-炔基）苯基醇或2-（1-炔基）-3-（羟甲基）吡啶的碘环化，可以在温和的条件下以优异的产率制备各种碘取代异铬烯、二氢异苯呋喃和吡喃吡啶。反应在15°C的MeCN中进行，碘源为3等量的I2，碱为NaHCO3（3等量）。反应的区域化学结果在很大程度上取决于起始物质的取代模式。特别是，在含有叔醇基的底物中，由于双烷基效应，观察到5-外环化模式导致二氢异苯并呋喃，而在含有伯或仲醇基的底物中，通常优选的途径是6-内环化模式，导致异铬或吡喃吡啶
A variety of iodo-substituted isochromenes, dihydroisobenzofurans, and pyranopyridines are readily prepared in good to excellent yields under mild conditions by the iodocyclization of readily available 2-(1-alkynyl)benzylic alcohols or 2-(1-alkynyl)-3-(hydroxymethyl)pyridines. Reactions are carried out in MeCN at 15 °C using 3 equiv of I2 as the iodine source and NaHCO3 (3 equiv) as the base. The regiochemical outcome of the reaction strongly depends on the substitution pattern of the starting material. In particular, the 5-exo-dig cyclization mode, leading to dihydroisobenzofurans, is observed in the case of substrates bearing a tertiary alcoholic group, owing to the gem-dialkyl effect, while the 6-endo-dig cyclization mode, leading to isochromene or pyranopyridines, is the usually preferred pathway in the case of substrates bearing a primary or secondary alcoholic group
登录
查看更多内容
影响因子：
2.8
作者：
Bew, Sean P.;El-Taeb, Gamila M. M.;Tan, Wen-Fei
通讯作者：
Tan, Wen-Fei
影响因子：
3.6
作者：
Arimitsu, Satoru;Jacobsen, Jesse M.;Hammond, Gerald B.
通讯作者：
Hammond, Gerald B.
影响因子：
15
作者：
Barluenga, J;Vázquez-Villa, H;González, JM
通讯作者：
González, JM
影响因子：
3.8
作者：
ALI, S;READ, RW;SOTHEESWARAN, S
通讯作者：
SOTHEESWARAN, S
影响因子：
1.8
作者：
Amjad, M;Knight, DW
通讯作者：
Knight, DW