Treatment of various organic halides with phosphinic acid (hypophosphorous acid) in aqueous ethanol in the presence of a radical initiator and a base gave the corresponding reduced products in high yields. Addition of a base is indispensable for the reduction of halides by phosphinic acid. Allylic ether of o-iodophenol or 2-haloalkanal allylic acetal underwent radical cyclization under the same conditions
A Tin Hydride Designed To Facilitate Removal of Tin Species from Products of Stannane-Mediated Radical Reactions
作者:Derrick L. J. Clive、Jian Wang
DOI:10.1021/jo010885c
日期:2002.2.1
Bu3SnH and Ph3SnH in standard free radical reactions, but with the special characteristic that the tin-containing byproducts are easily and very largely removed by mild hydrolysis (LiOH-water-THF or TsOH-water-THF), which converts them into base-soluble (aqueous NaHCO3) materials. The performance of stannane 1 was evaluated for a range of radical reactions involving halides, selenides, Barton-McCombie
易于制备的锡烷1在标准的自由基反应中的行为与常规试剂Bu3SnH和Ph3SnH相似,但具有的特殊特征是,通过温和水解(LiOH-水-THF)可轻松且大量去除含锡副产物或TsOH-水-THF),将其转化为碱溶性(NaHCO3水溶液)。在一系列涉及卤化物,硒化物,Barton-McCombie脱氧和烯炔环化的自由基反应中,评估了锡烷1的性能。在一些情况下,通过1 H NMR监测后处理程序在去除锡中的有效性。
Dipyrrolidinomethylaminophosphoric acid triamide (DPMPA) as an activator for the samarium diiodide-mediated reduction of alkyl and aryl halides
作者:Chriss E. McDonald、Jeremy R. Ramsey、David G. Sampsell、Laura A. Anderson、Jordan E. Krebs、Samantha N. Smith
DOI:10.1016/j.tet.2013.02.025
日期:2013.4
The use of the conjugate base of dipyrrolidinomethylaminophosphoric triamide (DPMPA−) as an activator of samariumdiiodide is reported. This phosphoramidate has been shown to be a very potent ligand, allowing for the efficient, low-temperature reduction of alkyl and aryl chlorides. Reductive cyclizations of haloalkenylnaphthalenes are also reported.
Stannylated Vinylic Addition Polynorbornene: Probing a Reagent for Friendly Tin-Mediated Radical Processes
作者:Rodrigo García-Loma、Ana C. Albéniz
DOI:10.1002/ejoc.201700670
日期:2017.8.10
Vinylic addition polynorbornenes (VA-PNB) with stannyl functional groups have been prepared and used in tin-mediated radical dehalogenation reactions. The aliphatic and robust scaffold of VA-PNB is well suited for a support in radical processes. VA-PNB-(CH2)nSnHBu2 can be used as stoichiometric reagent and VA-PNB-(CH2)nSnBu2Cl as catalyst in the presence of a hydride donor for the reduction of RBr
Diastereo- and Enantioselective Carbolithiation of Allyl <i>o</i>-Lithioaryl Ethers. New Chiral Cyclopropane Derivatives
作者:José Barluenga、Francisco J. Fañanás、Roberto Sanz、César Marcos
DOI:10.1021/ol026078x
日期:2002.6.1
[reaction: see text] Different allyl 2-lithioaryl ethers undergo a tandem carbolithiation/gamma-elimination in Et(2)O/TMEDA affording o-cyclopropyl phenol or naphthol derivatives in a diastereoselective manner. The use of (-)-sparteine as a chiral ligand instead of TMEDA allows the synthesis of cyclopropane derivatives with up 81% ee.