In Situ Formed Acetal-Facilitated Synthesis of Substituted Indene Derivatives from o-Alkenylbenzaldehydes
摘要:
A new protocol has been developed for the synthesis of indene derivatives, in a diastereoselective manner from,o-alkenylbenzaldehydes and enolizable ketones hi the presence of trimethyl orthoformate and catalytic triflic acid. This method involves tandem in situ formed acetal-assisted Claisen-Schmidt condensation followed by 5-exo-trig cyclization/Michael addition in one-pot. It has also been shown that the chalcones derived from o-alkenylbenzaldehydes and ketones can effectively be transformed into indene derivatives in the presence of TfOH catalyst alone.
Rh(III)-Catalyzed Olefination of N-Sulfonyl Imines: Synthesis of Ortho-Olefinated Benzaldehydes
摘要:
Rh(III)-catalyzed olefination of N-sulfonyl imines using acrylates and styrenes has been achieved for the synthesis of ortho-olefinated benaldehydes. This reaction proceeds via a chelation assisted C-H olefination/in situ hydrolysis process.