A Domino Palladium-Catalyzed Cyclization: One-Pot Synthesis of 4b-Alkyl-10-phenyl-4b,5-dihydroindeno[2,1-a]indenes via Carbopalladation Followed by C–H Activation

Abstract

An effective domino one-pot [Pd]-catalysis for the construction of novel tetracyclic compounds was described. This process involved in the construction of three C-C bonds from simple and readily available 1-bromo-2-isopropenylbenzenes and internal alkynes. A variety of fused tetracyclic dihydroindeno-indenes were accomplished.

Direct Synthesis of Napthalenes by Nickel‐Catalyzed Cascade Cyclization of o‐Vinyl Chlorobenzenes with Internal Alkynes

“…Based on our our experimental results and previous reports, [14] a plausible mechanism is proposed in Scheme 6. Oxidative addition of 1 to Ni(0) species generated in situ gives an arylnickel intermediate A.…”

“…Interestingly, the scope of the cascade cyclization was successfully extended to aliphatic substituents, affording the corresponding products in moderate to good yields (3 k-o), whereas the palladium-catalyzed cascade cyclization of o-vinyl bromobenzenes (R 1 = alkyl) with internal alkynes generated tetracyclic products. [14] In addition, 1-chloro-2-vinylbenzene (R 1 = H) failed to react at all (3 p). Diverse substituents (R 2 ) of 1 were also well tolerated, the presence of an electron-donating or electron-withdrawing group of substitutes at 4,5 position of 1 were well tolerated, leading to the corresponding products in good to high yields (3 p-t).…”

Synthesis of Substituted Naphthalenes by 1,4‐Palladium Migration Involved Annulation with Internal Alkynes

“…High reaction yields were observed when the position of phenyl ring A was installed by a variety of substituted phenyl groups (3aa-3ga), as well as naphthalenyl (3ha) and thienyl (3ia) groups. While the phenyl ring A was replaced by a methyl group, a substrate used recently in the coupling with alkyne for the preparation of tetracyclic compounds, [14] the desired naphthalene 3ja was still produced under our reaction conditions, albeit in reduced yield. An ester group was also compatible (3ka), which provides a useful handle for further derivati- zation.…”

[Pd]‐Catalyzed Intermolecular Coupling and Acid Mediated Intramolecular Cyclodehydration: One‐Pot Synthesis of Indenes

“…To the best of our knowledge, there is no general strategy for the one‐pot synthesis of indenes by the combination of transition metal catalyzed carbonyl formation followed by acid‐induced intramolecular condensation. In continuation of our interest to develop one‐pot domino processes, we present an efficient one‐pot synthetic strategy for the formation of 3‐aryl indenes by means of a Heck coupling followed by acid‐mediated cyclodehydration starting from simple allylic alcohols.…”