1888-41-1Relevant articles and documents
Switchable cascade C-H annulation to polycyclic pyryliums and pyridiniums: Discovering mitochondria-Targeting fluorescent probes
Chen, Xingyu,Yan, Lipeng,Liu, Yanhong,Yang, Yudong,You, Jingsong
supporting information, p. 15080 - 15083 (2020/12/22)
Disclosed herein is a counterion additive-switched rhodium-catalyzed cascade triple C-H annulation of 4-hydroxy-1-naphthaldehydes with alkynes, in which six chemical bonds are formed in one-pot. This reaction enables the rapid assembly of diverse polycycl
Asymmetric Alkynylation of β-Ketoesters and Naphthols Promoted by New Chiral Biphenylic Iodanes
Companys, Simon,Peixoto, Philippe A.,Bosset, Cyril,Chassaing, Stefan,Miqueu, Karinne,Sotiropoulos, Jean-Marc,Pouységu, Laurent,Quideau, Stéphane
, p. 13309 - 13313 (2017/10/05)
The preparation of new chiral biphenylic λ3-iodane reagents bearing transferable alkynyl ligands is described. These reagents transfer their carbon-based ligands onto β-ketoesters with an enantiomeric excess (ee) up to 68 %, and most remarkably, enable the dearomative alkynylation of naphthols in good to high yields up to 84 % ee.
Photo-Wolff rearrangement of 2-Diazo-1,2-naphthoquinone: Stern-Volmer analysis of the stepwise reaction pathway
Ladinig, Manfred,Ramseier, Markus,Wirz, Jakob
, p. 678 - 683 (2015/05/13)
Abstract 2-Diazo-1,2-naphthoquinone (1) and its derivatives are the photoactive components in Novolak photoresists. A femtosecond infrared study has established that the photoreaction of 1 proceeds largely by a concerted Wolff rearrangement yielding the ketene 1H-inden-1-ylidene-methanone (3) within 300 fs after excitation, but earlier trapping studies gave evidence for a minor reaction path via a carbene intermediate 1-oxo-2(1H)-naphthalenylidene (2) with a lifetime of about 10 ps. Here, we provide a quantitative assessment of the stepwise pathway by Stern-Volmer analysis of the trapping of 2 by methanol to yield 2-methoxy-1-naphthol (4). We conclude that the lifetime of the carbene 2 is at least 200 ps. Moreover, [3 + 2]cycloaddition of 2 and acetonitrile yielding 2-methylnaphth[2,1-d]oxazole (5) was observed. A comparison of the yields of 5 formed upon photolysis and upon thermolysis of 1 in acetonitrile provides evidence that a substantial part of the hot nascent carbene 2 formed photolytically rearranges to the ketene 3 during its vibrational relaxation (hot ground-state reaction). A quantitative assessment of the stepwise versus concerted photodeazotization pathways of 2-diazo-1,2-naphthoquinone (1) forming ketene 3 is provided. Trapping of the carbene intermediate 2 by methanol yields 2-methoxy-1-naphthol (4) in up to 12% yield. [3+2]Cycloaddition of 2 and acetonitrile yielding 2-methylnaphth[2,1-d]oxazole (5) was also observed. The lifetime of the thermalized carbene 2 is at least 200 ps. A comparison of the yields of 5 formed upon photolysis and upon thermolysis of 1 in acetonitrile provides evidence that a substantial part of the hot nascent carbene 2 formed photolytically rearranges to the ketene 3 during its vibrational relaxation (hot ground-state reaction).
