炔烃的立体选择性加氢构成构造立体烯烃的关键方法之一。大多数常规方法利用贵金属和有毒金属催化剂。这项研究涉及一种由工业化学品乙酰丙酮铁(II)和氢化二异丁基铝组成的简单催化剂,该催化剂能够在接近环境条件(1-3 bar H2、30°C,5 mol%[Fe] )。既不需要复杂的催化剂制备也不需要添加配体。机理研究(动力学中毒,X射线吸收光谱法,TEM)强烈表明了小铁簇和颗粒催化剂的运行。
Efficient coupling reactions of lithium alkynyl(triisopropoxy)borates with aryl halides: application to the antifungal terbinafine synthesis
作者:Chang Ho Oh、Seung Hyun Jung
DOI:10.1016/s0040-4039(00)01543-4
日期:2000.10
Thermally stable lithiumalkynyl(triisopropoxy)borates were reacted with several aryl halides in the presence of palladium catalysts to give the corresponding cross-coupling products in excellent yields. The present methodology has been successfully applied to the antifungal terbinafine synthesis.
Neopentylphosphines as effective ligands in palladium-catalyzed cross-couplings of aryl bromides and chlorides
作者:Lensey L. Hill、Joanna M. Smith、William S. Brown、Lucas R. Moore、Paul Guevera、Emily S. Pair、Jake Porter、Joe Chou、Christopher J. Wolterman、Raluca Craciun、David A. Dixon、Kevin H. Shaughnessy
DOI:10.1016/j.tet.2008.02.037
日期:2008.7
The use of neopentylphosphine ligands in the palladium-catalyzed Suzuki, Sonogashira, Heck, and Hartwig–Buchwald couplings of arylbromides and chlorides are reported. Di-tert-butylneopentylphosphine (DTBNpP) provided highly active catalysts for the coupling of arylbromides at mild temperatures. Trineopentylphosphine, an air-stable trialkylphosphine, gave inactive catalysts at room temperature, but
Copper-NHC-Mediated Semihydrogenation and Hydroboration of Alkynes: Enhanced Catalytic Activity Using Ring-Expanded Carbenes
作者:Jonathan W. Hall、Darcy M. L. Unson、Paul Brunel、Lee R. Collins、Mateusz K. Cybulski、Mary F. Mahon、Michael K. Whittlesey
DOI:10.1021/acs.organomet.8b00467
日期:2018.9.24
tert-butoxide complexes bearing five-, six-, and seven-membered ring N-heterocycliccarbenes, prepared by protonolysis of (NHC)CuMes with tBuOH, have been used as catalytic precursors in the semihydrogenation of alkynes with silanes/tBuOH and the hydroboration of alkynes with HBPin. Both processes proceed with high regioselectivity and show enhancements with six- and seven-membered ring carbenes.
由(NHC)CuMes与t BuOH质子分解制得的一系列带有五元,六元和七元环N-杂环卡宾的二配位叔丁醇铜配合物已被用作苯甲酸半加氢反应的催化前体。炔烃与硅烷/ t BuOH的混合,以及炔烃与HBPin的硼氢化。两种方法都具有较高的区域选择性,并显示六元和七元环卡宾具有增强作用。
Microwave-Assisted Copper-Catalyzed Cross-Coupling Reaction of Alkynes with Aryl Iodides and Vinyl Halides
作者:Chin-Fa Lee、Wen-Ting Tsai、Yun-Yung Lin、Yu-Jen Wang
DOI:10.1055/s-0031-1290813
日期:2012.5
copper-catalyzed coupling of terminalalkynes with aryl iodides and vinyl halides is reported. In general, the reactions are completed in 10–30 min using 2–5 mol% [CuI(xantphos)] as a catalyst to provide the corresponding alkynes and enynes in good to excellent yields. A broad spectrum of aryl iodides, vinyl iodides, and bromides are coupled with aryl- and alkyl alkynes. The microwave-assisted, copper-catalyzed
Stereoselective Chromium‐Catalyzed Semi‐Hydrogenation of Alkynes
作者:Bernhard J. Gregori、Michal Nowakowski、Anke Schoch、Simon Pöllath、Josef Zweck、Matthias Bauer、Axel Jacobi von Wangelin
DOI:10.1002/cctc.202000994
日期:2020.11.5
very little applications as hydrogenation catalysts. Here, we report a Cr‐catalyzed semi‐hydrogenation of internal alkynes to the corresponding Z‐alkenes with good stereocontrol (up to 99/1 for dialkyl alkynes). The catalyst comprises the commercial reagents chromium(III) acetylacetonate, Cr(acac)3, and diisobutylaluminium hydride, DIBAL−H, in THF. The semi‐hydrogenation operates at mild conditions