An analysis of the influences dictating regioselectivity in platinum-catalyzed hydrosilylations of internal alkynes
作者:Douglas A. Rooke、Zachary A. Menard、Eric M. Ferreira
DOI:10.1016/j.tet.2014.03.012
日期:2014.7
A full account of our studies on internal alkyne hydrosilylations using platinum catalysis is described. We demonstrate that these transformations are highly governed by the electronic characteristics of the alkyne substituents, wherein the hydride will add preferentially to the more electron-deficient alkyne carbon. The steric and coordinative capabilities of the substituents influence the selectivity
完整介绍了我们对使用铂催化的内部炔烃氢甲硅烷基化的研究。我们证明,这些转变高度受炔烃取代基的电子特性支配,其中氢化物将优先添加至电子欠缺的炔烃碳上。取代基的空间和配位能力对选择性的影响程度要小得多,其中丙炔醇是唯一的例外。硅烷的选择在某些情况下是相关的。特定的硅烷将提供较高的区域选择性,而其他的则选择性要低得多。最终,使用13 C NMR化学位移数据可以完全预测加成的区域选择性,从而将这种反应性纳入目标反应设计中。
Efficient synthesis of alkynyl amides via aminocarbonylation of iodoalkynes
作者:Péter Szuroczki、Borbála Boros、László Kollár
DOI:10.1016/j.tet.2018.09.001
日期:2018.10
aminocarbonylated with tert-butylamine undercarbonmonoxide atmosphere in the presence of in situ palladium(0) catalysts. The formation of the unsaturated carboxamide (alkynyl amide) is always accompanied by that of the Glaser coupling product, diphenylbutadiyne. The yield of the amide-forming reaction was optimised by the systematic variation of the phosphine ligand, carbonmonoxide pressure and temperature.
The synthesis of alk-2-ynl Weinreb amides via Pd/Cu-catalysed oxidative carbonylation of terminal alkynes
作者:Bharati Mourya、Sandip T. Gadge、Bhalchandra M. Bhanage
DOI:10.1039/d4ob00290c
日期:——
alk-2-ynl-Weinreb amides via Pd-catalyzed oxidative carbonylation of terminal alkynes and N,O-dimethylhydroxylamine hydrochloride at room temperature under low CO/O2 pressure is reported for the first time. This protocol offers tolerance of various functional groups under mild reaction conditions. The protocol incorporates aromatic- and aliphatic-substituted alkynes through a one-step oxidative carbonylative route
Palladium-Catalyzed Hiyama Couplings of α-Silylenoates and α-Silylenamides
作者:Douglas A. Rooke、Eric M. Ferreira
DOI:10.1021/ol301300r
日期:2012.7.6
The Hiyama couplings of both alpha-silylenoates and alpha-silylenamides are described. These sensitive substrate classes require particularly specific conditions, employing both appropriate silicon-based species and a silver additive to realize high yields of the coupling products. Regioselective platinum-catalyzed hydrosilylations provide a direct and convenient entry into these stereodefined trisubstituted alkenes.
New Syntheses of Some Functionalized and Acetylenic .beta.-Keto Phosphonates
作者:Isabelle Delamarche、Paul Mosset
DOI:10.1021/jo00097a058
日期:1994.9
beta-Keto phosphonates omega-functionalized by an ester group 1a-f, by a hydroxyl 5, and with a triple bond conjugated to the carbonyl group 2a-c were prepared by reacting dimethyl (lithiomethyl)phosphonate (3) with adequate electrophiles. Cyclic anhydrides such as succinic, and- glutaric anhydrides were employed for the synthesis of the two first homologs 1a and 1b. To obtain the other longer homologs 1c-f, 3-acylthiazolidine-2-thiones 7a-d easily prepared using cheap 2-mercaptothiazoline proved to be the electrophiles of choice. On the other hand, the synthesis of keto phosphonates 2a-c required the use of N-methoxy-N-methylamides.