Visible Light-Mediated Atom Transfer Radical Addition via Oxidative and Reductive Quenching of Photocatalysts
作者:Carl-Johan Wallentin、John D. Nguyen、Peter Finkbeiner、Corey R. J. Stephenson
DOI:10.1021/ja300798k
日期:2012.5.30
visible light-mediated atom transfer radical addition (ATRA) of haloalkanes onto alkenes and alkynes using the reductive and oxidativequenching of [IrdF(CF(3))ppy}(2)(dtbbpy)]PF(6) and [Ru(bpy)(3)]Cl(2) is presented. Initial investigations indicated that the oxidativequenching of photocatalysts could effectively be utilized for ATRA, and since that report, the protocol has been expanded by broadening
Benzophenone<i>vs</i>. Copper/Benzophenone in Light-Promoted Atom Transfer Radical Additions (ATRAs): Highly Effective Iodoperfluoroalkylation of Alkenes/Alkynes and Mechanistic Studies
作者:Redouane Beniazza、Rachel Atkinson、Christelle Absalon、Frédéric Castet、Sergey A. Denisov、Nathan D. McClenaghan、Dominique Lastécouères、Jean-Marc Vincent
DOI:10.1002/adsc.201600501
日期:2016.9.15
redox processes. Mechanistic investigations using transient absorption spectroscopy revealed that a deactivation pathway of the benzophenone triplet (3BP*) is via its reaction with the methanol solvent. We propose that the generated radicals, in particular .CH2OH, play a key role in the initiation step forming Rf. by reacting with RfI, Rf. then entering a radical chain cycle. 1H NMR studies provided evidence
二苯甲酮2(BP)或光还原性铜(II)络合物1有效促进了末端烯烃和炔烃的碘过氟烷基化。尤其是,在低压汞灯(TLC =薄层色谱,6 W)照射365 nm时,甲醇中1摩尔%的BP可以实现快速反应,并具有出色的反应产率。配合物1和BP 2表现出非常相似的反应性,表明涉及1的反应很可能是由二苯甲酮的光活化过程而不是铜(I)/(II)氧化还原过程控制的。使用瞬态吸收光谱的机理研究表明,二苯甲酮三联体的失活途径(3BP *)是通过其与甲醇溶剂的反应来进行的。我们建议特别是生成的部首。CH 2 OH在形成R f的引发步骤中起关键作用。通过与R f I,R f反应。然后进入一个彻底的连锁循环。1 H NMR研究提供了证据,表明形成了大量(约7%NMR)半缩醛CH 3 OCH 2 OH,即之间可能发生的副产物。CH 2 OH和R ˚F I.最后,DFT计算表明,从三线态-三线态能量传递(TTET)工艺与瞬态吸收研究一致,在反应条件下,将3
Light-mediated iodoperfluoroalkylation of alkenes/alkynes catalyzed by chloride ions: role of halogen bonding
作者:Redouane Beniazza、Lionel Remisse、Damien Jardel、Dominique Lastécouères、Jean-Marc Vincent
DOI:10.1039/c8cc02765j
日期:——
deoxygenated methanol solutions containing catalytic amounts of NaCl or Bu4NCl. Preliminary mechanistic studies indicate that the light-promoted homolytic cleavage of the Rf–I bond that initiates the reaction is facilitated by the halogenbonding interaction between RfI and chloride ions.
描述了用于烯烃/炔烃的碘全氟烷基化的创新方法。这些反应,包括烯烃的碘三氟甲基化,在低强度的UVA辐射下,在含有催化量的NaCl或Bu 4 NCl的脱氧甲醇溶液中,非常有效地进行。初步的机理研究表明,R f I和氯离子之间的卤素键相互作用促进了引发反应的R f -I键的光促进均裂。