一些新的烯烃烷氧基铊(III)化合物,C6H5C(R1)(OR3)CH2Tl(OCOR2)2 [I],是由苯乙烯和α-甲基苯乙烯与乙酸铊(III)和异丁酸在各种醇中制备的。I(R1=H) 与碘化铜、溴化铜、氯化铜、氰化物和硫氰酸铜反应生成相应的烷基卤化物和拟卤化物,C6H5CH(OR3)CH2X[II],在各种有机溶剂中,乙腈是首选溶剂为了准备II。钾盐的加入对提高Ⅱ的收率有显着效果。卤代和假卤代脱卤发生在铊先前与烷基碳相连的位置。提出了一种离子协调的分子间方案作为制备 II 的反应机制。简要讨论了 I 的核磁共振和红外光谱数据。
Comparative study of the vicinal functionalization of olefins with 2:1 bromide/bromate and iodide/iodate reagents
作者:Manoj K. Agrawal、Subbarayappa Adimurthy、Bishwajit Ganguly、Pushpito K. Ghosh
DOI:10.1016/j.tet.2009.01.095
日期:2009.4
halohydrins, halo methyl ethers, and halo acetates from olefins using 2:1 Br−/BrO3− and I−/IO3− reagents. In many cases both reagents afforded products selectively in high yields. The highest halogen atom efficiencies attained were 97% and 93% for Br−/BrO3− and I−/IO3−, respectively. Of the two reagents, I−/IO3− was established to be the preferred reagent for vicinal functionalization of linear alkenes and
IPy2BF4-Mediated Rearrangements of 1,2-Difunctionalized Compounds and Olefins
作者:Francisco J. Fañanás、Mónica Álvarez-Pérez、Félix Rodríguez
DOI:10.1002/chem.200500070
日期:2005.10.7
Acetal derivatives are easily obtained from 1,2-difunctionalizedcompounds by a new reaction mediated by IPy2BF4 with a mechanism based on a 1,2-migration of aryl or alkyl groups. A new oxidative rearrangement reaction of olefins is also described. Moreover, when this metal-free protocol is applied to cyclic olefins, interesting ring-contraction reactions are observed. The new methodologies described
Regioselective vicinal functionalization of unactivated alkenes with sulfonium iodate(<scp>i</scp>) reagents under metal-free conditions
作者:Dodla S. Rao、Thurpu R. Reddy、Kalvacherla Babachary、Sudhir Kashyap
DOI:10.1039/c6ob01179a
日期:——
Metal-free, molecular iodine-free direct 1,2-difunctionalization of unactivated alkenes has been reported. The sulfoniumiodate(I) reagent efficiently promoted the intermolecular vicinal iodo-functionalization of a diverse range of olefins in a stereo and regioselective manner. This method enables the divergent and straightforward preparation of synthetically useful functionalities; β-iodocarboxylates
Silylium-Catalyzed Carbon-Carbon Coupling of Alkynylsilanes with (2-Bromo-1-methoxyethyl)arenes: Alternative Approaches
作者:Belén Rubial、Alfredo Ballesteros、José M. González
DOI:10.1002/ejoc.201800777
日期:2018.12.6
The catalytic coupling of the title compounds affords β‐halo‐substituted alkynes. The cationic nature of the C–C bond‐forming event is established and the actual competence of silylium species to catalyze this transformation is proved.
<i>N</i>-Iodosuccinimide: A Highly Effective Regioselective Reagent for Iodoesterification of Alkenes
作者:Aleti R. Reddy、Payare L. Sangwan、Praveen K. Chinthakindi、Saleem Farooq、Vidavalur Siddaiah、Surrinder Koul
DOI:10.1002/hlca.201200383
日期:2013.7
efficient method has been achieved for regioselective iodoesterification of alkenes with aliphatic and aromatic acids, and protected amino acids in the presence of N‐iodosuccinimide (NIS) in nearly quantitative yields. Optically enriched iodohydrins have been achieved by LiAlH4 (LAH) reduction of diastereoisomeric iodo esters.