521270-78-0Relevant articles and documents
A convenient synthesis of quinolines by reactions of o-isocyano-β- methoxystyrenes with nucleophiles
Kobayashi, Kazuhiro,Yoneda, Keiichi,Miyamoto, Kazuna,Morikawa, Osamu,Konishi, Hisatoshi
, p. 11639 - 11645 (2004)
2,4-Disubstituted quinolines have been synthesized by reactions of o-isocyano-β-methoxystyrenes, which can be easily prepared from commercially available o-aminophenyl ketones in three steps, with alkyl(or aryl)lithiums in generally good yields. Subsequently, o-isocyano-β- methoxystyrenes have also proved to react efficiently with lithium dialkylamides to afford the corresponding 4-substituted N,N-dialkylquinolin-2-amines in satisfactory yields. Graphical Abstract.
Isocyanide 2.0
Ahmadian-Moghaddam, Maryam,D?mling, Alexander,Patil, Pravin
supporting information, p. 6902 - 6911 (2020/11/09)
The isocyanide functionality due to its dichotomy between carbenoid and triple bond characters, with a nucleophilic and electrophilic terminal carbon, exhibits unusual reactivity in organic chemistry exemplified for example in the Ugi reaction. Unfortunately, the over proportional use of only a few isocyanides hampers novel discoveries about the fascinating reactivity of this functional group. The synthesis of a broad range of isocyanides with multiple functional groups is lengthy, inefficient, and exposes the chemist to hazardous fumes. Here we present an innovative isocyanide synthesis overcoming these problems by avoiding the aqueous workup which we exemplify by parallel synthesis from a 0.2 mmol scale performed in 96-well microtiter plates up to a 0.5 mol multigram scale. The advantages of our methodology include an increased synthesis speed, very mild conditions giving access to hitherto unknown or highly reactive classes of isocyanides, rapid access to large numbers of functionalized isocyanides, increased yields, high purity, proven scalability over 5 orders of magnitude, increased safety and less reaction waste resulting in a highly reduced environmental footprint. For example, the hitherto believed to be unstable 2-isocyanopyrimidine, 2-acylphenylisocyanides and even o-isocyanobenzaldehyde could be accessed on a preparative scale and their chemistry was explored. Our new isocyanide synthesis will enable easy access to uncharted isocyanide space and will result in many discoveries about the unusual reactivity of this functional group. This journal is
Isocyanide cyclization reactions: 4-methylene-4H-benzo[d][1,3]oxazine, 3-benzyl-4-methylene-3,4-dihydroquinazolines and 3-(4-benzyl)-3H-quinazolin-4- ones - Experiment and theory
Neue, Benedikt,Reiermann, Ralph,Froehlich, Roland,Wibbeling, Birgit,Bergander, Klaus,Wuerthwein, Ernst-Ulrich
, p. 4944 - 4952 (2013/08/23)
2-Isocyanoacetophenone (3a) was found to be an easily accessible starting material for the unexpected formation of various heterocyclic systems. Thus, a hitherto unknown rather unstable 4-methylene-4H-benzoxazine derivative 4, which could be characterized by NMR spectroscopy, was formed in situ by the reaction of 3a in the presence of weak acids. In the presence of benzylamines, a new class of 3,4-dihydroquinazoline derivatives 6 and their oxidation products, quinazolin-4-ones 9, were obtained. The starting materials and products were completely characterized by spectroscopic and X-ray analysis. The scope and limitations of these cyclization reactions were investigated under various reaction conditions. High-level quantum chemical calculations were carried out to elucidate the mechanisms leading to scaffolds 4 and 6. The calculations suggest that the formation of 4 and 6 involves the generation of an unusual six-membered N-heterocyclic carbene or its C-protonated form as a reaction intermediate, followed by tautomerisation. This mechanism might also be applicable to other isocyanide cyclization reactions. Copyright
