This communication describes the deproto-metalation of a large range of aromatics including heterocycles using a newly developed lithium–cadmium base; the reaction proceeds at room temperature with an excellent chemoselectivity and efficiency, and proved to be regioselective in most cases.
New lithium-zincate approaches for the selective functionalisation of pyrazine: direct dideprotozincation vs. nucleophilic alkylation
作者:Sharon E. Baillie、Victoria L. Blair、David C. Blakemore、Duncan Hay、Alan R. Kennedy、David C. Pryde、Eva Hevia
DOI:10.1039/c2cc16959b
日期:——
Comparing the reactivity of the related lithium zincates [(THF)LiZn(TMP)tBu2] (1) and [(PMDETA)LiZntBu3] (2) towards pyrazine discloses two new bimetallic approaches for the selective 2,5-dideprotonation and room temperature C–H alkylation of this sensitive heterocycle.
An air-stable microwire radial heterojunction with high photoconductivity based on a new building block
作者:Jianfeng Zhang、Jinshan Wang、Xinjun Xu、Shiyan Chen、Qinglin Zhang、Chuang Yao、Xiujuan Zhuang、Anlian Pan、Lidong Li
DOI:10.1039/c5tc01050k
日期:——
(dithienopyrazine) and utilized it as a shell material to construct organic 1D radial p–nheterojunctions. This p-type compound shows a higher oxidation potential and is more resistant to photooxidation in air than its analogs with the commonly-used benzodithiophene unit. Moreover, we prepared organic microwires with radial heterojunctions via a solution-processed method by self-assembly of our p-type material
Palladium(II)‐immobilized Triptycene based Hypercrosslinked Polymers: An Efficient, Green, and Reusable Heterogenous Catalyst for Suzuki‐Miyaura Cross‐coupling Reaction
作者:Atikur Hassan、Akanksha Singh Baghel、Amit Kumar、Neeladri Das
DOI:10.1002/asia.202300778
日期:2024.1.2
Pd(II)-immobilised triptycene based hyper-crosslinked porous organic polymer (Pd@TP-iHCP) was found to be an efficient and sustainable catalyst for Suzuki-Miyauracross-coupling (SMCC) reaction. The catalyst features facile synthesis, and reusability for several times without affecting the yield of the reactions.
Alkali-metal mediated zincation of N-heterocyclic substrates using the lithium zincate complex, (THF)Li(TMP)Zn(tBu)2 and applications in in situ cross coupling reactions
作者:Victoria L. Blair、David C. Blakemore、Duncan Hay、Eva Hevia、David C. Pryde
DOI:10.1016/j.tetlet.2011.06.090
日期:2011.9
This study investigates the ability of the mixed-metal reagent [Li(TMP)Zn(tBu)(2)] 1 to promote direct Zn-H exchange reactions (zincations) of a wide range of N-heterocyclic molecules. The generated metallated intermediates from these reactions are intercepted with I-2 and some of them are also employed as precursors in Pd-catalysed Negishi cross-coupling applications. A comparison with recent precedents in metallation chemistry reveals that for some of these heterocycles, 1 allows improved conversions, under milder conditions and in certain cases, even gives unique regioselectivities. (C) 2011 Elsevier Ltd. All rights reserved.