过渡金属催化的炔丙基亲电子试剂和格氏试剂的交叉偶联提供了高度官能化的产物,是极其有用的合成中间体。然而,由于具有挑战性的区域选择性,将炔丙基衍生物转化为炔丙基化合物的例子仍然有限。我们使用LaCl 3 ·2LiCl在没有配体的情况下催化格氏试剂的炔丙基化,具有高区域选择性和立体特异性。该方法显示了使用烷基或(杂)芳基格氏试剂和具有不同离去基团的炔基亲电子试剂的广泛底物范围。我们的方案进一步应用于叶毛多辛 B 的正式合成。利用天然丰富且相对无毒的镧催化剂的方法值得探索。
Palladium Nanoparticles Immobilized on Chemically Modified Silica Gel: Efficient Heterogeneous Catalyst for Suzuki, Stille and Sonogashira Cross-Coupling Reactions
作者:Piyali Dutta、Amitabha Sarkar
DOI:10.1002/adsc.201100168
日期:2011.10
Nanoparticulate palladium (Pdnp-2) supported on polyethylene glycol-functionalized silica gel is an excellent heterogeneous catalytic system for Suzuki, Sonogashira and Stille cross-coupling reactions that afford products in high yield. The immobilized palladiumnanoparticles were readily prepared by reaction of modified silica gel (1) with potassium tetrachloropalladate(II) in the presence of an acyl
Ni<sup>I</sup>Catalyzes the Regioselective Cross-Coupling of Alkylzinc Halides and Propargyl Bromides to Allenes
作者:Rita Soler-Yanes、Iván Arribas-Álvarez、Manuel Guisán-Ceinos、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/chem.201603758
日期:2017.1.31
We describe the unprecedented formation of allenes by Ni‐catalyzed cross‐coupling of propargyl bromides with alkylzinc halides. The reaction regioselectivity is complementary to the previously reported formation of propargyl‐coupled compounds. Experiments support the formation of NiI complexes as the active species and the participation of radical intermediates. Kinetic studies showed that the reaction
Multimetallic Ir–Sn3-catalyzed substitution reaction of π-activated alcohols with carbon and heteroatom nucleophiles
作者:Arnab Kumar Maity、Paresh Nath Chatterjee、Sujit Roy
DOI:10.1016/j.tet.2012.10.086
日期:2013.1
An atom economic and catalytic substitutionreaction of π-activated alcohols by a multimetallic Ir–Sn3 complex has been demonstrated. The multimetallic Ir–Sn3 complex can be easily synthesized from the reaction between [Cp∗IrCl2]2 and SnCl2. In presence of as little as 1 mol % of the catalyst three different types of π-activated alcohols, namely benzyl, allyl, and propargyl alcohols, have been successfully
Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: synthesis of propargyl alcohols and α-ketoesters
作者:Ke Ni、Ling-Guo Meng、Hongjie Ruan、Lei Wang
DOI:10.1039/c9cc04090k
日期:——
The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere.
可见光诱导的溴代炔与醇的偶联反应的化学选择性可以通过对反应气氛进行简单改变来控制。
Regioselective Iron‐Catalysed Cross‐Coupling Reaction of Aryl Propargylic Bromides and Aryl Grignard Reagents
作者:Inés Manjón‐Mata、M. Teresa Quirós、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/adsc.201901203
日期:2020.1.7
An iron‐catalysed Kumada‐type cross‐coupling reaction between aryl substituted propargylic bromides and arylmagnesium reagents has been developed. Propargylic coupling products were the main or only outcome, and propargyl/allene regioselectivity was shown to depend on the electronic nature of the substituents on the triple bond of the substrate and on the arylmagnesium halide. Best selectivities were