Oxidative addition of N-halosuccinimides to palladium(0): the discovery of neutral palladium(II) imidate complexes, which enhance Stille coupling of allylic and benzylic halides
作者:Catherine M. Crawforth、Suzanne Burling、Ian J.S. Fairlamb、Anant R. Kapdi、Richard J.K. Taylor、Adrian C. Whitwood
DOI:10.1016/j.tet.2005.06.080
日期:2005.10
mediate the Stille coupling of allylic and benzylichalides with alkenyl, aryl and allyl stannanes. In competition experiments between 4-nitrobromobenzene and benzyl bromide with a cis-stannylvinyl ester, (Ph3P)2Pd(N-Succ)Br preferentially cross-couples benzyl bromide, whereas with other commonly employed precatalysts 4-nitrobromobenzene undergoes preferential cross-coupling. Furthermore, preferential
Gold(<scp>i</scp>)-catalyzed cross-coupling reactions of aryldiazonium salts with organostannanes
作者:Manjur O. Akram、Popat S. Shinde、Chetan C. Chintawar、Nitin T. Patil
DOI:10.1039/c8ob00630j
日期:——
Gold(I)-catalyzed cross-couplingreactions of aryldiazonium salts with organostannanes are described. This redox neutral strategy offers an efficient approach to diverse biaryls, vinyl arenes and arylacetylenes. Monitoring the reaction with NMR and ESI-MS provided strong evidence for the in situ formation of Ph3PAuIR (R = aryl, vinyl and alkynyl) species which is crucial for the activation of aryldiazonium
描述了金(I)催化的芳基重氮盐与有机锡烷的交叉偶联反应。这种氧化还原中性策略为各种联芳基,乙烯基芳烃和芳基乙炔提供了一种有效的方法。用NMR和ESI-MS监测反应为原位形成Ph 3 PAu I R(R =芳基,乙烯基和炔基)物种提供了有力证据,这对于激活芳基重氮盐至关重要。
α-Silicon effect assisted Curtin–Hammett allylation using allylcopper reagents derived from 1,3-dienylsilanes
作者:Shang Gao、Ming Chen
DOI:10.1039/c9sc02905b
日期:——
Cu-catalyzed stereoselective synthesis of (E)-δ-silyl-anti-homoallylic alcoholsfrom 1,3-dienylsilane was developed. Mechanistic studies revealed that the borocupration of dienylsilane proceeded through a 1,2-addition pathway to give an allylcopper intermediate with Cu distal to the silyl group. However, the subsequent aldehyde allylation proceeded via Curtin–Hammett control to give (E)-δ-silyl-anti-homoallylic
Efficient and selective Stille cross-coupling of benzylic and allylic bromides using bromobis(triphenylphosphine)(N-succinimide)palladium(II)
作者:Catherine M. Crawforth、Ian J.S. Fairlamb、Richard J.K. Taylor
DOI:10.1016/j.tetlet.2003.11.014
日期:2004.1
[Pd(NCOC2H4CO)(PPh3)2Br] 1. Significantly, these reactions do not require the use of hexamethylphosphoramide (HMPA) as the solvent, or additional ligands, such as trifurylphosphine or triphenylarsine. Selectivity for benzyl bromide over bromobenzene is observed for precatalyst 1, against the precatalysts, bromobis(triphenylphosphine)(benzyl)palladium(II) and bis(triphenylphosphine)palladium(II) bromide.
使用预催化剂[Pd(NCOC 2 H 4 CO)(PPh 3)2 Br] 1可以使烯丙基和苄基溴与有机锡烷交联。重要的是,这些反应不需要使用六甲基磷酰胺(HMPA)作为溶剂,也不需要使用其他配体,例如三糠基膦或三苯基ar。对于预催化剂1,观察到苄基溴对溴苯的选择性相对于预催化剂溴双(三苯基膦)(苄基)钯(II)和双(三苯基膦)钯(II)。
Palladium-Catalyzed Coupling Reaction of an Enol Nonaflate with (Vinyl)tributylstannanes and Acetylenes: A Highly Stereoselective Synthesis of 8,18-<sup>13</sup>C<sub>2</sub>-Labeled Retinal
作者:Akimori Wada、Yasuhiro Ieki、Saeko Nakamura、Masayoshi Ito
DOI:10.1055/s-2005-865294
日期:——
Here we report that enol nonaflates exhibit higher reactivity than the corresponding enol triflates in palladium-catalyzed cross-coupling reactions with various (vinyl)tributylstannanes and acetylenes. We also highlight the reaction of a vinyl nonaflate, containing two 1 3 C-labeled carbon atoms with an alkenyl stannane, which afforded the trisubstituted E-olefin stereoselectively in high yield. The
在这里,我们报告烯醇九氟甲磺酸酯在钯催化的与各种(乙烯基)三丁基锡烷和乙炔的交叉偶联反应中表现出比相应的烯醇三氟甲磺酸酯更高的反应性。我们还强调了含有两个 1 3 C 标记的碳原子的乙烯基九烷基锡与烯基锡烷的反应,它以高产率立体选择性地提供了三取代的 E-烯烃。然后将 E-烯烃转化为相应的全 E-视黄醛。