氢化镍(II)配合物[(Me N 2 N)Ni-H](2)是通过[(Me N 2 N)Ni-OMe](6)与Ph 2 SiH 2反应合成的。 NMR和IR光谱以及X射线晶体学。2在溶液中不稳定,并通过两个反应途径分解。第一个途径是分子内NH还原性消除,得到Me N 2 NH和镍颗粒。第二种途径是分子间的,具有H 2,镍颗粒和五配位Ni(II)络合物[(Me N 2N)2 Ni](8)作为产物。2与丙酮和乙烯反应,分别形成[(Me N 2 N)Ni-O i Pr](9)和[(Me N 2 N)Ni-Et](10)。2也与卤代烷反应,生成卤化镍配合物和烷烃。使用[(Me N 2 N)Ni-Cl](1)作为催化剂,NaO i Pr或NaOMe作为碱,Ph 2 SiH 2或Me(EtO)2催化还原卤代烷SiH作为氢化物源。催化作用似乎是通过自由基机理进行的。
Nickel-Catalyzed Sonogashira Reactions of Non-activated Secondary Alkyl Bromides and Iodides
作者:Jun Yi、Xi Lu、Yan-Yan Sun、Bin Xiao、Lei Liu
DOI:10.1002/anie.201307069
日期:2013.11.18
A nicked reaction: The title reaction of terminal alkynes with non‐activated secondaryalkyliodides and bromides was accomplished for the first time. This reaction provides a new and practical approach for the synthesis of substituted alkynes (see scheme; cod=cyclo‐1,5‐octadiene).
Stereoselective synthesis of polyfunctional di- and trisubstituted cyclopentane derivatives using a new palladium catalyzed cyclization.
作者:Heinz Stadtmüller、Charles E. Tucker、Andrea Vaupel、Paul Knochel
DOI:10.1016/s0040-4039(00)61508-3
日期:1993.12
undergo a radical ring closure to give cyclopentylmethylzinc iodides when treated with Et2Zn in the presence of PdCl2(dppf) (2 mol %). In the case of 4-substituted 5-hexenyl iodides trans-cyclopentanes are obtained (> 99 : 1) whereas 1-substituted-5-hexenyl iodides provide cis-cyclopentanes (ca. 80 : 20). The presence of a substituent at both positions considerably improves the cis stereoselectivity up to
作者:Manuel Guisán-Ceinos、Rita Soler-Yanes、Daniel Collado-Sanz、Vilas B. Phapale、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/chem.201300882
日期:2013.6.24
reaction involving cyclization followed by cross‐coupling allows the formation of up to three alkyl–alkyl bonds in a single operation by using alkene‐containing alkyl iodides and Grignard reagents (see scheme; acac=acetylacetonate; TMEDA=N,N′,N′‐tetramethyl ethylenediamine). Mechanistic experimental and computational studies suggest a NiI–NiII–NiIII catalytic cycle and the intermediacy of radicals.
提出新颖的断开连接:强大的镍催化级联反应,包括环化和交叉偶联,通过使用含烯烃的烷基碘化物和格利雅试剂,一次操作最多可形成三个烷基-烷基键(请参阅方案; acac =乙酰丙酮酸酯) ; TMEDA = N,N ',N'-四甲基乙二胺)。力学实验和计算研究表明,Ni I –Ni II –Ni III催化循环和自由基的中介。
Copper-Catalyzed and Indium-Mediated Methoxycarbonylation of Unactivated Alkyl Iodides with Balloon CO
作者:Yanchi Chen、Lei Su、Hegui Gong
DOI:10.1021/acs.orglett.9b01573
日期:2019.6.21
This work emphasizes the synthesis of alkyl esters via Cu-catalyzed and In-mediated alkoxycarbonylation of unactivatedalkyliodides in the presence of In or InI. The reactions were suitable for the preparation of primary, secondary, and even tertiary alkyl esters, representing an exceptionally rare example for the creation of quaternary carbon centers upon formation of esters. The preliminary mechanistic
这项工作强调在In或InI的存在下,通过Cu催化和In介导的未活化烷基碘的烷氧基羰基化来合成烷基酯。该反应适合于伯,仲,甚至叔烷基酯的制备,代表了在形成酯时生成季碳中心的极为罕见的例子。初步的机理研究表明,涉及烷基自由基,而Cu / In / CO在羰基化事件中起着协同作用。
<i>Z</i>-Selective Olefin Synthesis via Iron-Catalyzed Reductive Coupling of Alkyl Halides with Terminal Arylalkynes
作者:Chi Wai Cheung、Fedor E. Zhurkin、Xile Hu
DOI:10.1021/jacs.5b01784
日期:2015.4.22
Selective catalytic synthesis of Z-olefins has been challenging. Here we describe a method to produce 1,2-disubstituted olefins in high Z selectivity via reductive cross-coupling of alkylhalides with terminal arylalkynes. The method employs inexpensive and nontoxic catalyst (iron(II) bromide) and reductant (zinc). The substrate scope encompasses primary, secondary, and tertiaryalkylhalides, and