Organocatalytic Synthesis of Methylene-Bridged <i>N</i>-Heterobiaryls
作者:David E. Stephens、Vu T. Nguyen、Bhuwan Chhetri、Emily R. Clark、Hadi D. Arman、Oleg V. Larionov
DOI:10.1021/acs.orglett.6b02719
日期:2016.11.18
N-heterobiaryls directly from the corresponding N-heterocycles in a reaction with methylmagnesium chloride in the presence of catalytic amounts of N,N,N′,N′-tetramethylethylenediamine under thermal and microwave conditions is reported. The split-and-merge methylenation of 2,2′-N-heterobiaryls and the direct ortho-alkylation of quinoline and isoquinoline with Grignardreagents have also been developed
Manganese‐Catalyzed Asymmetric Hydrogenation of Quinolines Enabled by π–π Interaction**
作者:Chenguang Liu、Mingyang Wang、Shihan Liu、Yujie Wang、Yong Peng、Yu Lan、Qiang Liu
DOI:10.1002/anie.202013540
日期:2021.3
The non‐noble metal‐catalyzed asymmetric hydrogenation of N‐heteroaromatics, quinolines, is reported. A new chiral pincer manganese catalyst showed outstanding catalytic activity in the asymmetric hydrogenation of quinolines, affording high yields and enantioselectivities (up to 97 % ee). A turnover number of 3840 was reached at a low catalyst loading (S/C=4000), which is competitive with the activity
报道了非贵金属催化的N-杂芳族化合物喹啉的不对称氢化。一种新型手性钳式锰催化剂在喹啉的不对称氢化中表现出出色的催化活性,提供了高收率和对映选择性(高达97%ee)。在低催化剂负载量(S / C = 4000)下,达到了3840的周转率,与该反应中最有效的贵金属催化剂的活性相竞争。对映选择性的精确调节通过π-π相互作用来保证。
Boron Dipyridylmethene (DIPYR) Dyes: Shedding Light on Pyridine-Based Chromophores
作者:Jessica H. Golden、John W. Facendola、Daniel Sylvinson M. R.、Cecilia Quintana Baez、Peter I. Djurovich、Mark E. Thompson
DOI:10.1021/acs.joc.7b00786
日期:2017.7.21
investigate the photophysicalproperties of three simple DIPYR dyes: boron dipyridylmethene, boron diquinolylmethene, and boron diisoquinolylmethene. The three dyes strongly absorb in the blue-green part of the spectrum (λem = 450–520 nm, ε = 2.9–11 × 104 M–1 cm–1) and display green fluorescence with high quantum yields (ΦPL = 0.2, 0.8, and 0.8, respectively). Key photophysicalproperties in these systems
硼二吡咯亚甲基(BODIPY)衍生物已被广泛用作荧光应用中的生色团,但对基于吡啶的BODIPY类似物(二吡啶基次甲基)的光物理性质知之甚少。实际上,已经报道了二氟化硼二吡啶基亚甲基(DIPYR)是无辐射的,并且DIPYR的衍生物具有适度的发光(如果有的话)。在这份报告中,我们探索了化学空间这个摸索不多的领域,并研究了三种简单的DIPYR染料的光物理性质:硼二吡啶基亚甲基,硼二喹啉基亚甲基和硼二异喹啉基亚甲基。三种染料在光谱的蓝绿色部分强烈吸收(λem = 450–520 nm,ε= 2.9–11×10 4 M –1 cm –1),并显示绿色荧光具有高量子产率(Φ PL = 0.2,0.8和0.8,分别地)。通过结合TD-DFT和扩展的多构型准生成第二级微扰理论(XMCQDPT2)方法对这些系统中的关键光物理性质进行了评估,并与实验结果进行了比较,结果表明,喹啉和异喹啉衍生物的高量子产率是该化合物的结果。母体结构苯并环合时,S
HMPA-Promoted Siladifluoromethylation of Di-, and Triarylmethanes with the Ruppert-Prakash Reagent
作者:Xinfei Ji、Xianghu Zhao、Hongyan Shi、Song Cao
DOI:10.1002/asia.201701224
日期:2017.11.2
Classical reagents, modern reaction: An HMPA-promoted siladifluoromethylation of di-, and triarylmethanes with TMSCF3 in the presence of LDA via cleavage of a C−F bond has been developed. The reactions proceeded rapidly and were completed at room temperature within 10 min, affording α-siladifluoromethylated di-, and triarylmethanes in moderate to excellent yields.
Reactivity of Copper Complexes with Bis(piperidinyl)methane and Bis(quinolinyl)methane Ligands
作者:Tim‐Daniel J. Stumpf、Manfred Steinbach、Christian Würtele、Jonathan Becker、Sabine Becker、Roland Fröhlich、Richard Göttlich、Siegfried Schindler
DOI:10.1002/ejic.201700755
日期:2017.10.10
Copper complexes with the ligands bispiperidine (BP) or bisquinoline (BQ) were investigated. A dinuclear carbonato bridged copper(II) complex as well as a dinuclear copper(I) complex with BP as ligand were structurally characterized. The reaction of a copper(I) BP complex investigated by low temperature stopped-flow techniques showed the very fast formation of a bis--oxido copper intermediate leading
研究了与配体双哌啶 (BP) 或双喹啉 (BQ) 的铜配合物。结构表征了双核碳酸桥联铜(II)配合物以及以BP为配体的双核铜(I)配合物。通过低温停流技术研究的铜 (I) BP 络合物的反应表明,双--氧化铜中间体的快速形成导致分子内配体羟基化。然而,底物例如苯甲醇也可以被这种复合物氧化。相比之下,当使用 BQ 或该配体的衍生物时,无法通过光谱观察到中间体。相反,当氯化铜 (II) 与作为配体的 BQ 在空气中或在惰性条件下反应时,观察到了复杂的反应行为。几种晶体结构有助于建立这些反应的机制。通过这种方式获得的一个有趣的反应产物是一种新的配位聚合物。