Substrate dependent intramolecular palladium-catalysed cyclisation and subsequent β-H elimination or C–H activation: a general method for the synthesis of fused pyran rings

Ligand‐free CuI‐catalyzed coupling and cyclization of β‐bromo‐α,β‐unsaturated amides with formamide leading to pyrimidinones

“…As part of our continuing studies directed towards transition metal‐catalyzed cyclization reactions, we recently disclosed new synthetic methods for the formation of several carbo‐ and heterocyclic compounds using β‐bromo‐α,β‐unsaturated aldehydes and their derivatives via such an intrinsic coupling and cyclization . The β‐bromo‐α,β‐unsaturated aldehydes and their derivatives can be readily prepared from the corresponding α‐methylene‐containing ketones by the bromination conditions of the Vilsmeier–Haak reaction and subsequent transformation and used as a building block for the synthesis of versatile cyclic compounds . In connection with this report, Ma et al .…”

CuI/amino acid‐catalyzed coupling and cyclization of β‐bromo‐α,β‐unsaturated amides with terminal alkynes leading to (3Z)‐3‐alkylidenepyrrol‐1‐ones

“…Such a similar coupling followed by cyclization was also exemplified by the reaction of 2‐bromobenzamides and terminal alkynes in the presence of CuI and l ‐proline . On the other hand, during the course of our ongoing studies on palladium‐catalyzed cyclization reactions using β‐bromo‐α,β‐unsaturated aldehydes and their derivatives, which are readily prepared from α‐methylene containing ketones under bromination conditions of Vilsmeier–Haack reaction and subsequent transformation, we have disclosed several new synthetic methods for the synthesis of carbo‐ and heterocyclic compounds cyclization of β‐bromo‐α,β‐unsaturated amides with terminal alkynes leading to (3 Z )‐3‐alkylidenepyrrol‐1‐ones.…”

Palladium‐catalyzed carbonylative cyclization of 1‐bromoallyl bromides with anilines leading to 1‐aryl‐1H‐pyrrol‐2(5H)‐ones

“…Transition metal‐catalyzed carbonylation followed by cyclization (carbonylative cyclization) has been widely explored and used as a promising synthetic tool for the construction of the structural core of many pharmacologically and biologically active lactones and lactams . In connection with this report, it is known that β‐bromo‐α,β‐unsaturated aldehydes and their derivatives, which are readily prepared from the corresponding ketones by Vilsmeier–Haack reaction and subsequent transformation, are used as a building block for the construction of versatile cyclic compounds . As part of our continuing studies directed towards palladium‐catalyzed cyclization reactions using β‐bromo‐α,β‐unsaturated aldehydes and their derivatives, we reported on the synthesis of several heterocycles via such a carbonylative cyclization .…”