已经开发出在绿光照射下工作的中度氧化的硫氧杂草光氧化还原催化剂。这些催化剂表现出相对适中的激发态还原电位 [ E 1/2 (C*/C •– ) = 1.75–1.94 V vs 饱和甘汞电极 (SCE)] 并且可以有效地促进自由基阳离子 Diels-Alder 反应。绿灯。有趣的是,β-卤代苯乙烯(E p/2 = 1.57–1.61 V vs SCE)具有良好的耐受性,可提供合成有用的卤代环己烯。
已经开发了在绿光照射下操作的基于硫杂蒽鎓的有机光还原催化剂。这些催化剂具有较高的激发态还原电位(E 0 '(C ∗ / C -)= + 1.79–1.94 V vs SCE)。它们能够在绿光或蓝光辐射下有效活化亲二烯体,从而以高收率获得了目标自由基阳离子Diels-Alder环加合物。本发明的基于噻吨鎓的催化剂提供了新的绿光驱动的光氧化还原催化体系。
organophotoredox catalysts that operate under irradiation with green light have been developed. These catalysts present high excited-state reduction potentials (E0′(C∗/C−) = +1.79–1.94 V vs SCE). They are able to efficiently activate dienophiles under green or blue light irradiation afforded the targeted radicalcation Diels-Alder cycloadducts in good yields. The present thioxanthylium-based catalysts provide
已经开发了在绿光照射下操作的基于硫杂蒽鎓的有机光还原催化剂。这些催化剂具有较高的激发态还原电位(E 0 '(C ∗ / C -)= + 1.79–1.94 V vs SCE)。它们能够在绿光或蓝光辐射下有效活化亲二烯体,从而以高收率获得了目标自由基阳离子Diels-Alder环加合物。本发明的基于噻吨鎓的催化剂提供了新的绿光驱动的光氧化还原催化体系。
Redox Potential Controlled Selective Oxidation of Styrenes for Regio- and Stereoselective Crossed Intermolecular [2 + 2] Cycloaddition <i>via</i> Organophotoredox Catalysis
cross-cycloaddition has been developed in the presence of a thioxanthylium photoredox catalyst. Electron-rich styrenes such as β-bromostyrene (Ep/2 = +1.61 V vs SCE) were selectively oxidized by a thioxanthylium photoredox catalyst (E1/2 (C*/C•–) = +1.76 V vs SCE) to styryl radical cations and reacted with styrene (Ep/2 = +1.97 V vs SCE) to furnish polysubstituted cyclobutanes in high yields. The present reaction
在噻吨锡光氧化还原催化剂的存在下,已经开发了氧化还原电势控制的分子间[2 + 2]交叉环加成反应。富含电子的苯乙烯(例如β-溴苯乙烯)(E p / 2 = +1.61 V vs SCE)被硫代蒽醌光氧化还原催化剂(E 1/2(C * / C •–)= +1.76 V vs SCE)选择性氧化为苯乙烯基阳离子与苯乙烯反应(E p / 2 = +1.97 V vs SCE),以高收率提供多取代的环丁烷。本反应可成功地用于β-卤代苯乙烯的分子间[2 + 2]交叉环加成,这是迄今为止报道的代表性有机光氧化还原催化剂无法有效实现的。
Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts
thioxanthylium salts has been developed. The reaction of diaryl sulfides with benzoyl chlorides in the presence of TfOH smoothly proceeded to give the desired thioxanthylium salts in good yields. In their UV–vis spectra, the maximum absorption wavelengths of methoxy-functionalized thioxanthylium salts were observed at around 460 nm, which show a drastic red shift compared to the parent thioxanthylium salts. The
Iron-mediated C–H coupling of arenes and unactivated terminal alkenes directed by sulfur
作者:Craig W. Cavanagh、Miles H. Aukland、Alan Hennessy、David J. Procter
DOI:10.1039/c5cc02676h
日期:——
A sulfur-directed Fe(iii)-mediated ortho C–H coupling of arenes with unactivated terminal alkenes gives products of regioselective alkene chloroarylation.
Iron-mediated oxidative C–H coupling of arenes and alkenes directed by sulfur: an expedient route to dihydrobenzofurans
作者:Craig W. Cavanagh、Miles H. Aukland、Quentin Laurent、Alan Hennessy、David J. Procter
DOI:10.1039/c6ob00883f
日期:——
ortho-coupling of arenes and unactivated terminal alkenes mediated by iron, and a palladium-catalysed deallylation/heterocyclisation sequence. The iron-mediated coupling affords linear products of alkene chloroarylation in good yield and with complete regioselectivity. The coupling likely proceeds by redox-activation of the arene partner by iron(III) and alkene addition to the resultant radicalcation.