报道了足够缺电子的氟化芳烃和官能化的N-芳基-N'-甲硅烷基二氮烯作为掩蔽的芳基亲核试剂的化学选择性 C(sp 2 )-C(sp 2 ) 偶联。氟化物促进的转化涉及原位生成用各种敏感官能团修饰的芳基亲核试剂,然后逐步进行亲核芳族取代 (S N Ar)。这些反应通常在室温下在几分钟内进行。这种催化过程允许两个偶联伙伴的功能化,以良好的产率提供高度氟化的联芳基化合物。
General Synthesis and Optical Properties of N-Aryl-N′-Silyldiazenes
摘要:
While organo-substituted diazenes (R-1-N=N-R-2 with R = alkyl, aryl) are a well-studied class, of compounds, much less is known about their heavier group 14 analogues, notably because of their perceived instability. We report herein a general oxidative protocol to prepare various N-aryl-N'-silyldiazenes by a fast and mild dehydrogenation of the corresponding silylhydrazines using di-tert-butylazodicar-boxylate as an oxidant. The optical properties of these stable blue to purple silyldiazenes were also studied by UV/visible absorption spectroscopy and supported by TD-DFT calculations.
Synthesis of Non‐Symmetric Azoarenes by Palladium‐Catalyzed Cross‐Coupling of Silicon‐Masked Diazenyl Anions and (Hetero)Aryl Halides
作者:Lucie Finck、Martin Oestreich
DOI:10.1002/anie.202210907
日期:2022.10.4
non-symmetric azobenzene derivatives by an unprecedented C(sp2)−N(sp2) cross-coupling is presented. N-Aryl-N′-silyldiazenes are employed as diazenyl anion equivalents that can be selectively coupled under palladium catalysis with a large array of (hetero)aryl bromides in high yields. The functional-group tolerance on either (hetero)aryl ring is excellent.
Fluoride-Catalyzed Arylation of α-(Trifluoromethyl)styrene Derivatives with Silicon-Masked, Functionalized Aryl Pronucleophiles
作者:Aliyaah J. M. Rahman、Yannan Xu、Martin Oestreich
DOI:10.1021/acs.orglett.3c02021
日期:2023.8.4
arylation of α-(trifluoromethyl)styrene derivatives with silicon-protected functionalized aryl pronucleophiles is disclosed. Catalytic amounts of an anionic Lewis base such as fluoride trigger the release of the aryl nucleophile from N-aryl-N′-silyldiazenes by desilylation along with denitrogenation. The thus-generated carbon nucleophiles engage in an allylic displacement with α-(trifluoromethyl)styrene electrophiles
Palladium-Catalyzed Denitrogenative Cross-Coupling of Silicon-Masked, Aryl-Substituted Diazenes and Aryl Bromides
作者:Lucie Finck、Sarah Dabrowski、Martin Oestreich
DOI:10.1055/a-1988-6052
日期:——
A denitrogenative palladium-catalyzed C(sp2)–C(sp2) cross-coupling of aryl-substituted diazenes capped with a trimethylsilyl group and functionalized arylbromides is reported. A PEPPSI™ catalyst in the presence of NaOt-Bu enables the activation of the N-aryl-N′-silyldiazene pronucleophile with concomitant loss of dinitrogen and subsequent coupling of the in-situ-formed aryl nucleophile. By this, biaryl
报道了一种脱氮钯催化的 C(sp 2 )–C(sp 2 ) 交叉偶联,芳基取代的二氮烯被三甲基甲硅烷基和功能化的芳基溴化物封端。存在 NaO t -Bu 的PEPPSI ™ 催化剂能够激活N -芳基 - N '-甲硅烷基二氮烯亲核试剂,同时失去二氮并随后偶联原位形成的芳基亲核试剂。由此,可以制备带有各种取代基的联芳基化合物。
Synthesis of Benzhydryl-Substituted Amines by Silanolate-Mediated Aldimine Arylation with Functionalized Aryl Nucleophiles Released from Diazene-Based Reagents
作者:Aliyaah J. M. Rahman、Lucie Finck、Wolfgang Obermayer、Martin Oestreich
DOI:10.1021/acs.orglett.2c03798
日期:2022.12.16
imine derivatives with functionalized aryl pronucleophiles is reported. The aryl nucleophiles are released from silicon-protected aryl-substituted diazenes by desilylation with potassium trimethylsilanolate concomitant with the loss of dinitrogen. A broad range of functional groups is tolerated in the aryl nucleophile but, depending upon their electronic effect, require specific groups at the imine