Arylcyclopropane photochemistry. Effects of electron-donating and electron-withdrawing aromatic substituents on the photochemical rearrangements of 1,1-diarylcyclopropanes
The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp<sup>3</sup>)–O Arylation
作者:L. Reginald Mills、John J. Monteith、Gabriel dos Passos Gomes、Alán Aspuru-Guzik、Sophie A. L. Rousseaux
DOI:10.1021/jacs.0c06904
日期:2020.7.29
understand and predict reactivity is highly important for the development of new reactions. In the context of Ni-catalyzed C(sp3)-O functionalization, we have developed a unique strategy employing activated cyclopropanols to aid the design and optimization of a redox-active leavinggroup for C(sp3)-O arylation. In this chemistry, the cyclopropane ring acts as a reporter of leaving-group reactivity, since the
Supported transition-metal catalysts for the CC coupling reaction between ethene and diazoalkanes
作者:M.E. Schneider、U. Möhring、H. Werner
DOI:10.1016/0022-328x(96)06397-8
日期:1996.8
The preparation of a series of immobilized transition-metal catalysts are reported. The catalysts were obtained by chemisorption of either rhodium(I) or iridium(I) complexes [MX(C2H4)2]n (M Rh, Ir; X Cl, OAc, acac, f3-acac, f6-acac) on SiO2 or MgO supports. The oxides were also activated by SiCl4 or TiCl4 to give support materials in which the acidic nature of the surface is substantially increased
报道了一系列固定化过渡金属催化剂的制备。通过铑(I)或铱(I)配合物[MX(C 2 H 4)2 ] n(MRh,Ir; X Cl,OAc,acac,f 3 -acac,f SiO 2或MgO载体上的6 -acac)。氧化物也通过SiCl 4或TiCl 4活化,得到载体材料,其中表面的酸性大大提高。测试了固定化催化剂的活性,特别是在乙烯与二苯基重氮甲烷的反应中,生成了1.1-二苯基丙烯的混合物(8)和1.1-二苯基环丙烷(9)。发现活性最高,选择性最高(比率最高为8:9 )的催化剂B1形成了载体材料B(由SiCl 4活化的SiO 2)和[RhCl(C 2 H 4)2 ] 2(1),并且B1的活性和选择性与溶液中的复合物1相当。与此相反,负载型催化剂A2,D2和A3,D3从铑[Rh(OAc)(C获得的2 ħ4)2 ] 2(2)和[Rh(acac)(C 2 H 4)2 ](3)在溶液中的活性低
Control of Redox‐Active Ester Reactivity Enables a General Cross‐Electrophile Approach to Access Arylated Strained Rings**
作者:Daniel C. Salgueiro、Benjamin K. Chi、Ilia A. Guzei、Pablo García‐Reynaga、Daniel J. Weix
DOI:10.1002/anie.202205673
日期:2022.8.15
Aliphatic strained rings can be (hetero)arylated through a decarboxylative cross-electrophile coupling. The keys to this advance are: 1) a new ligand that enables tolerance of a variety of strained ring classes and 2) electronic tunability of redox-active esters to control the rate of radical generation.