The Benzyne Aza‐Claisen Reaction

Abstract

Ein Arin und ein tertiäres Allylamin liefern durch eine Aza‐Claisen‐Umlagerung o‐Allylanilinprodukte. Das Arin bietet sowohl die π‐Komponente für die Umlagerung als auch die Quaternisierung, die die Aktivierungsenergie der sigmatropen Verschiebung senkt. Die Reaktion wurde zur Synthese benzanellierter cyclischer Amine mit mittlerer Ringgröße genutzt (siehe Schema).magnified image

Hydrogen‐Bonding Directed Assembly and Gelation of Donor–Acceptor Chromophores: Supramolecular Reorganization from a Charge‐Transfer State to a Self‐Sorted State

“…However, an extensive literature search revealed that no example of this type of sequential reaction has been reported so far. Whilst several examples of benzyne‐mediated cyclization/functionalization7 with simple electrophiles have been described, their scope is limited owing to the use of strong bases, such as t BuLi or s BuLi 8…”

Transition-Metal-Free Synthesis of Benzo-Fused Five- and Six-Membered Heterocycles Employing Arynes

“…Greaney and coworkers developed a unique aryne aza-Claisen reaction, using tertiary allyl amines and arynes as a coupling partners [104]. In many cases, the reaction is initiated by the nucleophilic addition of nitrogen into arynes followed by the rearrangement to form the desired products.…”

“…Additionally, these compounds found application as synthetic intermediates for the preparation of biologically important complex molecules (for example "cortistatin") [37]. SCHEME 77 Aryne aza-Claisen rearrangement to synthesize medium-sized heterocycles [104]. SCHEME 77 Aryne aza-Claisen rearrangement to synthesize medium-sized heterocycles [104].…”

Attempts Directed towards the Synthesis of Intermediate (Aryne)chromium Complexes from Aryl Triflates and from (Haloarene)chromium Complexes

“…[11][12][13][14][15][16] Of these, elimination from aryl triflates [15] is currently most frequently used. [7][8][9][10][17][18][19][20][21][22][23][24][25][26] The field has recently been reviewed by Lloyd-Jones. [27] In the context of our interest in (arene)tricarbonylchromium complexes we attempted to generate (aryne)tricarbonylchromium complexes 1 as reactive intermediates.…”