87779-92-8Relevant academic research and scientific papers
Delineating ligand effects in intramolecular aryl amidation reactions: formation of a novel spiro-heterocycle by a tandem cyclisation process
Cropper, Emma L.,Yuen, Aui-Ping,Ford, Agnes,White, Andrew J.P.,(Mimi) Hii, King Kuok
experimental part, p. 525 - 530 (2009/04/07)
Ligand effects for intramolecular Pd-catalysed aryl amidation reaction were examined for the synthesis of seven-membered benzolactam rings. In an attempt to produce an eight-membered ring, tandem C-N/C-O bond forming reactions occurred to give a novel spi
Effect of chain length on radical to carbanion cyclo-coupling of bromoaryl alkyl-linked oxazolines: 1,3-Areneotropic migration of oxazolines
Marshall, Laura J.,Roydhouse, Mark D.,Slawin, Alexandra M. Z.,Walton, John C.
, p. 898 - 911 (2007/10/03)
(Chemical Equation Presented) 2-Halophenylalkyl-2-oxazolines with alkyl chain spacers of two to six C atoms (n = 0-4) were prepared and their S RN1-type reactions with several base systems examined. The best conditions to promote cyclocoupling to the corresponding benzocycloalkane derivatives involved use of LDA in THF. The precursors with 3-C-atom and 4-C-atom spacers gave good yields of 2-(1′-phenylindan-1′-yl)-2- oxazolines and 2-(1-phenyl-1,2,3,4-tetrahydronaphthalen-1-yl)-2-oxazoline, respectively. The major products from the precursor with a 5-C-atom spacer were derivatives of benzocycloheptane in which the oxazoline group had undergone a novel areneotropic migration from the end of the spacer to the benzo ring. The product from reaction of the corresponding 2-C-atom precursor was a 9-oxazolinophenanthrene derivative. EPR spectroscopy showed the intermediates of the LDA-promoted reactions to be radical anions of the product benzocycloalkanes. This supported an SRN1-type chain mechanism involving initial production of aryl radicals connected to azaenolate ions via the spacer groups. Intramolecular radical to carbanion coupling then generated ring-closed benzocycloalkane radical anions that transferred an electron to more precursor. Diastereoselective radical to carbanion cyclo-coupling reactions were carried out with 2-bromophenylpropyl precursors containing chiral 2-oxazolines. The diastereoselectivity achievable was modest, but the product diastereoisomeric Indane derivatives were easily separable by chromatography.
