1225573-75-0Relevant academic research and scientific papers
Ring expansion of 1,2,3,4-tetrahydroisoquinolines to dibenzo[c,f]azonines. An unexpected [1,4]-sigmatropic rearrangement of nitrile-stabilized ammonium ylides
Orejarena Pacheco, Julio Cesar,Opatz, Till
, p. 5182 - 5192 (2014)
When the products of a Strecker reaction of 1,2,3,4-tetrahydroisoquinolines with aromatic aldehydes are quaternized with alkyl triflates and subsequently treated with base, a ring expansion to 6,7,8,13-tetrahydro-5H-dibenzo[c,f] azonine-5-carbonitriles takes place. The nine-membered cyclic products can be obtained in good yields (78-89%) in a process involving the [1,4]-sigmatropic rearrangement of a nitrile-stabilized ammonium ylide. The reaction sequence provides a new, simple, and efficient method for the synthesis of these unusual N-heterocycles.
