Reaction des lithiens avec les organophosphores. Reaction d'addition du t-butyllithium sur le noyau benzenique des sels de phenylphosphoniums

A new reaction of organolithium compounds with phosphonium salts is described; reaction of t-butyllithium with dibenzylaminophosphonium or tetraphenylphosphonium bromides takes place through addition of the t-butyl group on a benzene ring at the position para to the phosphorus atom, the ylid formed reacts in a characteristic Wittig reaction with p-tolylaldehyde.     

Pd/C-catalyzed room-temperature hydrodehalogenation of aryl halides with hydrazine hydrochloride

Treatment of aryl and heteroaryl halides with catalytic amounts of Pd/C in the presence of hydrazine hydrochloride in basic medium (sodium hydroxide or sodium t-butylate) at room temperature leads to the corresponding hydrodehalogenation products with high selectivity. Aryl iodides, bromides, chlorides and fluorides can be reduced using this reagent combination. The reduction is compatible with various electron-donating or electron-withdrawing groups.