Iridium(<scp>i</scp>) complexes bearing hemilabile coumarin-functionalised N-heterocyclic carbene ligands with application as alkyne hydrosilylation catalysts
作者:Mert Olgun Karataş、Bülent Alıcı、Vincenzo Passarelli、Ismail Özdemir、Jesús J. Pérez-Torrente、Ricardo Castarlenas
DOI:10.1039/d1dt01946e
日期:——
A set of iridium(I) complexes of formula IrCl(κC,η2-IRCouR′)(cod) or IrCl(κC, η2-BzIRCouR′)(cod) (cod = 1,5-cyclooctadiene; Cou = coumarin; I = imidazolin-2-carbene; BzI = benzimidazolin-2-carbene) have beeen prepared from the corresponding azolium salt and [Ir(μ-OMe)(cod)]2 in THF at room temperature. The crystalline structures of 4b and 5b show a distorted trigonal bipyramidal configuration in the
一组铱(我)式的IrCl的复合物(κ Ç,η 2 -I - [R凑R' )(COD)或的IrCl(κ Ç,η 2 -BzI ř凑R' )(COD)(COD = 1, 5-环辛二烯;Cou = 香豆素;I = 咪唑啉-2-卡宾;BzI = 苯并咪唑啉-2-卡宾)在室温下由相应的唑鎓盐和 [Ir(μ-OMe)(cod)] 2在 THF 中制备. 4b和5b的晶体结构显示了在固态下具有协调的香豆素部分的扭曲三角双锥构型。相比之下,由于吡喃酮环的半化能力,在溶液中观察到该五配位结构与相关方形平面异构体之间的平衡。分别在低温和高温极限下实现了两种物质的 NMR 表征。此外,平衡的热力学参数 Δ H R和 Δ S R是通过 VT 1 H NMR 光谱获得的,并且落在 22-33 kJ mol -1和 72-113 J mol -1 K -1 的范围内,分别。IrCl(κ C ,η 2-BzI Tol
Dichotomy of Manganese Catalysis via Organometallic or Radical Mechanism: Stereodivergent Hydrosilylation of Alkynes
作者:Xiaoxu Yang、Congyang Wang
DOI:10.1002/anie.201710206
日期:2018.1.22
Herein, we disclose the first manganese‐catalyzed hydrosilylation of alkynes featuring diverse selectivities. The highly selective formation of E‐products was achieved by using mononuclear MnBr(CO)5 with the arsenic ligand, AsPh3. Whereas using the dinuclear catalyst Mn2(CO)10 and LPO (dilauroyl peroxide) enabled the reversed generation of Z‐products in good to excellent stereo‐ and regioselectivity
the Si–H bond in silanes for the hydrosilylation of alkynes has been developed. The mild protocol operates efficiently with high regioselectivity (anti-Markovnikov) and stereoselectivity (Z/E ratio ranges from 92:8 to >99:1), providing a wide range of Z-vinylsilanes in high yields. Moreover, visible-light-induced manganese-catalyzed activation of the Ge–H bond for E-selective alkyne hydrogermylation
Hydrosilylation of alkynes catalyzed by ruthenium carbene complexes
作者:Sarah V. Maifeld、Michael N. Tran、Daesung Lee
DOI:10.1016/j.tetlet.2004.11.025
日期:2005.1
Hydrosilylation of terminal alkynes with a variety of silanes catalyzed by Cl2(PCy3)2RuCHPh (1) affords mainly the Z-isomer via trans addition in excellent yields. The presence of a hydroxyl group in close proximity to the triple bond was observed to exert a strong directing effect, resulting in the highly selective formation of the α-isomer. Intramolecular hydrosilylation of a homopropargylic silyl
A synthon for a 14-electron Ir(iii) species: catalyst for highly selective β-(Z) hydrosilylation of terminal alkynes
作者:Manuel Iglesias、María Pérez-Nicolás、Pablo J. Sanz Miguel、Victor Polo、Francisco J. Fernández-Alvarez、Jesús J. Pérez-Torrente、Luis A. Oro
DOI:10.1039/c2cc34931k
日期:——
A synthon for a 14-electron Ir(III) species is described. The geometrical control exerted by the ligand system over the Irâalkenyl intermediate in hydrosilylation of terminal alkynes precludes formation of the more thermodynamically stable β-(E)-vinylsilane, thus affording the β-(Z) isomer in excellent yields.