邻位官能化的偶氮苯在分子开关后备受追捧,因为它们可以调整为在可见光范围内吸收,并且 ( Z )-异构体可以具有高热半衰期。为了能够直接访问这些目标,我们开发了一种通过新型邻位取代偶氮苯功能化二芳基碘盐的合成路线。在温和、无过渡金属的条件下,将偶氮苯部分选择性地转移至 O-、N-、C- 和 S- 亲核试剂,可以获得前所未有的邻位取代偶氮苯。研究了试剂的光开关特性,并通过 X 射线晶体学确定了结构。
邻位官能化的偶氮苯在分子开关后备受追捧,因为它们可以调整为在可见光范围内吸收,并且 ( Z )-异构体可以具有高热半衰期。为了能够直接访问这些目标,我们开发了一种通过新型邻位取代偶氮苯功能化二芳基碘盐的合成路线。在温和、无过渡金属的条件下,将偶氮苯部分选择性地转移至 O-、N-、C- 和 S- 亲核试剂,可以获得前所未有的邻位取代偶氮苯。研究了试剂的光开关特性,并通过 X 射线晶体学确定了结构。
Unusual Reaction of Azoxybenzenes with<i>p</i>-Toluenesulfonic Acid in Acetic Anhydride
作者:Ichiro Shimao、Ken Fujimori、Shigeru Oae
DOI:10.1246/bcsj.55.1538
日期:1982.5
azoxybenzene with p-toluenesulfonic acid in aceticanhydride gave tosylates of 4- and 2-(phenylazo)phenols, and the corresponding acetates as by-product, besides azobenzene. However, a similar reaction of 4,4′-difluoroazoxybenzene gave 2-tosyloxy-4,4′-difluoroazobenzene as rearrangement product, besides 4-fluorophenyl tosylate and 4-fluorophenyl acetate. Meanwhile, the reaction of 4,4′-diacetoxyazoxybenzene
Hypercrosslinked Polymer Platform-Anchored Single-Site Heterogeneous Pd–NHC Catalysts for Diverse C–H Functionalization
作者:Tanmoy Mandal、Moumita Mondal、Joyanta Choudhury
DOI:10.1021/acs.organomet.1c00182
日期:2021.8.9
new class of hypercrosslinked polymer (HCP) platform-anchored single-site heterogenized Pd–NHC catalysts for multipurpose C–H functionalization reactions. This new class is represented by a set of three catalysts, viz., HCP-B-MeNHC-Pd, HCP-B-BnNHC-Pd, and HCP-TPM-MeNHC-Pd, having a variation on the structural feature of the anchoring polymeric platform. All three catalysts were fully characterized via
我们展示了一类新的超交联聚合物(HCP)平台锚定的单点异质化 Pd-NHC 催化剂,用于多用途 C-H 功能化反应。这一新类别由一组三种催化剂代表,即HCP-B- Me NHC-Pd、HCP-B- Bn NHC-Pd和HCP-TPM- Me NHC-Pd,在结构特征上有变化锚定聚合物平台。所有三种催化剂都通过各种固态表征和分析技术(如 X 射线光电子能谱、13C 交叉极化魔角自旋核磁共振、场发射扫描电子显微镜、能量色散 X 射线分析、热重分析和电感耦合等离子体-光发射光谱法。三种经常使用且非常有用的 C-H 官能化反应,即 C-H 卤化、乙酰氧基化和芳基化,用新催化剂进行了测试,发现它们具有高度的相容性和成功性。使用HCP-TPM- Me NHC-Pd在催化剂的作用下,卤化、乙酰氧基化和芳基化反应的官能化产物的产率分别高达 85%、75% 和 70%。这种新系统提供了诸如增强的活性、异质性和可回收性等苛刻的特性,使其成为非均相
A Highly Selective Catalytic Method for the Oxidative Functionalization of C−H Bonds
作者:Allison R. Dick、Kami L. Hull、Melanie S. Sanford
DOI:10.1021/ja031543m
日期:2004.3.3
This communication describes a new and highly practical Pd(II)-catalyzed method for the regio- and chemoselective oxidative functionalization of arenes and alkanes. Carbon-hydrogen bonds of substrates that contain a variety of directing groups (e.g., pyridine, azobenzene, pyrazole, and imine derivatives) are selectively transformed into esters, ethers, and aryl-halides under mild conditions. The scope
AbstractA method of directsynthesis of ortho-acyloxylated azoarenes via palladium-catalyzed C–Hbondactivation was developed. The reaction proceeded was smoothly at room temprature and have better yield in shorter times. The obtained ortho-acyloxylated azoarenes could be efficiently converted into 2-hydroxyazobenzenes in good yields through a hydrolysis process.Graphical AbstractMany various ortho-acyloxylated
Palladium-Catalyzed Acetoxylation of Arenes by Novel Sulfinyl N-Heterocyclic Carbene Ligand Complexes
作者:Francisco Tato、Andrés Garcı́a-Domı́nguez、Diego J. Cárdenas
DOI:10.1021/om400981x
日期:2013.12.23
A series of novel ligands based on N-heterocyclic carbene and sulfoxide functionalities have been prepared and characterized. Pd(II) complexes have been synthesized by transmetalation from the corresponding NHC-Ag derivatives, and their behavior as catalysts has been studied in arene C H bond oxidative activation. Studies conducted toward the elucidation of the reaction mechanism of the acetoxylation suggest a C-H activation step at Pd(IV) rather than Pd(II) intermediates.