Iodine(III)-Promoted Ring Expansion of 1-Vinylcycloalkanol Derivatives: A Metal-Free Approach toward Seven-Membered Rings
作者:Luiz F. Silva,、Ramon S. Vasconcelos、Mário A. Nogueira
DOI:10.1021/ol800048f
日期:2008.3.1
A versatile and metal-free approach for the synthesis of molecules bearing seven- and eight-membered rings is described. The strategy is based on the ringexpansion of 1-vinylcycloalkanols (or the corresponding silyl or methyl ether) mediated by the hypervalent iodine reagent HTIB (PhI(OH)OTs). The reaction condition can be easily adjusted to give seven-membered rings bearing different functional groups
Seven-Membered Rings through Metal-Free Rearrangement Mediated by Hypervalent Iodine
作者:Siguara Silva、Adriana Torre、João de Carvalho、Ana Ruiz、Luiz Silva
DOI:10.3390/molecules20011475
日期:——
for the synthesis of carbocycles and of heterocycles bearing seven- and eight-membered rings is described. The strategy is based on ring expansion of 1-vinylcycloalkanols (or the corresponding silyl or methyl ether) mediated by the hypervalent iodine reagent HTIB (PhI(OH)OTs). Reaction conditions can be easily adjusted to give ring expansion products bearing different functional groups. A route to medium-ring
Electrochemical Oxidative Aryl(alkyl)trifluoromethylation of Allyl Alcohols via 1,2-Migration
作者:Zhipeng Guan、Huamin Wang、Yange Huang、Yunkun Wang、Shengchun Wang、Aiwen Lei
DOI:10.1021/acs.orglett.9b01518
日期:2019.6.21
An electrochemical oxidative difunctionalization of allyl alcohols for the synthesis of β-trifluoromethyl ketones is achieved through a 1,2-migration process. A series of β-trifluoromethyl ketones can be facilely obtained utilizing CF3SO2Na as a radical source, eliminating the use of metals and sacrificial chemical oxidants. Importantly, this protocol not only realizes aryl migration but also offers
通过1,2-迁移过程可实现烯丙醇的电化学氧化双官能化,以合成β-三氟甲基酮。利用CF 3 SO 2 Na作为自由基源可以轻松获得一系列β-三氟甲基酮,而无需使用金属和牺牲性化学氧化剂。重要的是,该协议不仅实现了芳基迁移,而且还提供了烷基迁移产物。另外,电化学催化的环膨胀和克级反应证明了该方案的合成有用性。
I2/Li2CO3-promoted cyanation of diarylalcohols through a dual activation process
One-step base promoted strategy for cyanation of α,α-diaryl alcohols has been developed under mild and transition metal-free conditions. This method provides a straightforward and facile way towards the synthesis of β,γ-unsaturated nitriles and α-phenylnitiriles from α-vinyl carbinols and α,α-diaryl methanols, respectively, up to 99% yield. Moreover, various azides and ethers could also be accessed
Copper-Free Asymmetric Allylic Alkylation of Trisubstituted Cyclic Allyl Bromides Using Grignard Reagents
作者:David Grassi、Alexandre Alexakis
DOI:10.1002/anie.201307591
日期:2013.12.16
AAA: The asymmetric allylic alkylation (AAA) of trisubstituted cyclic allyl bromides with Grignardreagents is catalytic (2 mol % of ligand) and regioselective (SN2'/SN2=91:9→100:0). The quaternary carbon centers are formed with good to high enantioselectivity (e.r.=81.5:19.5→96:4).