Nickel-Promoted Oxidative ipso-Annulation of N-( p-Methoxyaryl)propiolamides with α-Carbonyl Alkyl Bromides.

A new route to producing 3-alkyl spiro[4,5]trienones via nickel-promoted radical oxidative ipso-annulation of N-( p-methoxyaryl)propiolamides with α-carbonyl alkyl bromides using TBHP oxidant is described. The method allows the formation of three new C-C bonds through a sequence of oxidative C-Br bond cleavage, ipso-cyclization and dearomatization, and represents a new alkyne 1,2-difunctionalization to access to the construction of spiro[4,5]trienones. [ABSTRACT FROM AUTHOR]