Organometallic Chemistry sans Organometallic Reagents: Modulated Electron‐Transfer Reactions of Subvalent Early Transition Metal Salts
作者:John J. Eisch、Xian Shi、Joseph R. Alila、Sven Thiele
DOI:10.1002/cber.19971300903
日期:1997.9
reductant, titanium dichloride, has been throughly examined, as well as the analogous ZrCl2 and HfCl2 reagents, all of which are readily obtainable by the alkylative reduction of the Group tetrachloride by butyllithium in THF. Noteworthy is that such interactions of MCl4 with butyllithium in hydrocarbon media lead, in contrast, to M(III) or M(IV) halide hydrides. Analogous alkylative reductions in THF
to butyl) arylketones have been found to undergo multiple arylation on the alkyl chains accompanied by oxidative unsaturation upon treatment with excess aryl bromides in the presence of a palladium catalyst and a base. In the case of phenyl propyl ketones, for example, the arylation occurs up to five times on the α-and γ-positions as well as the ortho-position of the phenyl ring to give 1-(biphenyl-2-yl)-2
X-ray Absorption and Electron Paramagnetic Resonance Guided Discovery of the Cu-Catalyzed Synthesis of Multiaryl-Substituted Furans from Aryl Styrene and Ketones Using DMSO as the Oxidant
serving not only as a solvent but also as an oxidant to promote the oxidation of Cu(I) to Cu(II) has been demonstrated. X-ray absorption and electron paramagnetic resonance evidence revealed a single-electron redox process where DMSO could oxidize Cu(I) to Cu(II). The novel discovery guided the rational design of copper-catalyzed oxidative cyclization of aryl ketones with styrenes to furans, providing a new
Synthesis of a new hypervalent iodine compound, [2-(hydroxydimethylsilyl)phenyl](phenyl)iodonium triflate as a convenient approach to benzyne
作者:Tsugio Kitamura、Zhaohong Meng、Yuzo Fujiwara
DOI:10.1016/s0040-4039(00)01128-x
日期:2000.8
A new benzyneprecursor, [2-(hydroxydimethylsilyl)phenyl](phenyl)iodonium triflate, is prepared from 1,2-dibromobenzene in good yield. This procedure avoids the use of carcinogenic HMPA and the severe reaction conditions. The reaction of the benzyneprecursor with Bu4NF in the presence of a trapping agent under very mild conditions efficiently generates benzyne and gives the benzyne adduct in high
Rh(I)-Catalyzed Carbene Migration/Carbonylation/Cyclization: Straightforward Construction of Fully Substituted Aryne Precursors
作者:Guohao Zhu、Wen-Chao Gao、Xuefeng Jiang
DOI:10.1021/jacs.0c13012
日期:2021.1.27
The Rh(I)-catalyzed cascade formation of carbenoid followed by a carbonylative cyclization of silyl diynes has been established to achieve diverse ortho silyl-substituted phenolics, enabling access to fully substituted aryne precursors via a one-step fluorosulfurylation. The silyl mask on the termini of alkynes is demonstrated not only to suppress the undesired oxidation but also to control the selectivity
已经建立了 Rh(I) 催化级联形成卡宾,然后甲硅烷基二炔的羰基化环化,以实现多种邻甲硅烷基取代的酚类化合物,从而能够通过一步氟磺酰化获得完全取代的芳炔前体。炔烃末端的甲硅烷基掩膜不仅可以抑制不需要的氧化,还可以控制 CO 插入的选择性。全面建立了对完全取代芳烃的直接访问,并将其应用于多环芳族分子的高效构建。