Some new aspects of benzyne and radical mediated cyclisations

KNH2/NH3 cyclisations of some alkoxy substituted arylhalides proceed in poor yields. This shortcoming may be overcome by the use of LDA/THF to effect the ring closure which may occur through benzyne or radical intermediates. Besides ortho halogenated dihydroanils and amides, the cyclisation of the benzylamine Schiff bases also provides a convenient route to isoquinoline alkaloids

Organic synthesis via photoinduced hydrogen and electron transfer reactions

Synthetic utility of photoinduced intramolecular hydrogen transfer reactions of ketones, amides, imines, nitrites and nitro compounds is highlighted by illustrative examples. Role of light-initiated electron transfer from amines, mercaptans, aryl groups and from lithiated ketones, amides and imines in reactions of synthetic interest is discussed

Synthesis of the grass alkaloid perlolidine through a pyridyne cyclisation reaction^†

1129-1131A synthesis of the grass alkaloid perlolidine is described in which the key step involves the pyridyne cyclisation of 2-benzyloxy-5-bromo-3-[(N-phenyl) aminomethyl] pyridine

New routes to condensed polynuclear compounds: Part XVIII-Cyclisations through naphthynes and pyridynes

It has been shown that the KNH2/NH3 cyclisation of ortho/meta halogenated Schiff bases, or the corresponding dihydro compounds, succeeds when 1,2-naphthynes and 2,3-pyridynes are involved as intermediates. Using this procedure 3-aza-benzo[j]phenanthridine, 9-azaphenanthridine and 2,11-diazachrysene have been synthesized