Construction of dibenzo-fused seven- to nine-membered carbocycles via Brønsted acid-promoted intramolecular Friedel–Crafts-type alkenylation

Abstract

Brønsted acid-promoted intramolecular hydroarylation of alkynylbenzenes carrying an arylalkyl group at the ortho-position leads to alkylidenedibenzo[a,d]cycloheptenes, -octenes and -nonenes in up to quantitative yield with complete regioselectivity. The scope and limitation of this reaction and application to the synthesis of tricyclic antidepressants are described.

An Integrated Approach toward NanoBRET Tracers for Analysis of GPCR Ligand Engagement

“…In addition, the presence of a reactive exocyclic double bond could render many late-stage chemistries inapplicable. We sought to employ a recently reported elegant approach to Amitriptyline’s skeleton [ 41 ], which could provide a straightforward path to aryl-substituted Amitriptylines. Indeed, this approach delivered four amine-reactive carboxy-modified Amitriptylines in a fast and expedient manner ( Figure S7 ).…”

Pd/C and TFA‐promoted One‐pot, Two‐step Cascade Reaction: An Effective Synthesis of Oxepines

“…On the basis of our own experimental observations and existing literature precedence, [4,22] the plausible reaction mechanism was depicted as shown in scheme 3. We assume that the reaction might be initiated by the Pd/C‐catalyzed reaction of 1 a coupling with a terminal acetylene to afford the intermediate 3 aa , followed by the sequential activation of alkyne by acid species to form the complex E‐2 .…”

“…The reaction of 1 a and 2 a was completed within 11 h under standard conditions, generating the desired product (4 aa) in 85% (0.789 g) yield (Scheme 2a). As discussed above, the formation of 7-phenyl-6H-benzo [6,7]oxepino [3,2-c] On the basis of our own experimental observations and existing literature precedence, [4,22] the plausible reaction mechanism was depicted as shown in scheme 3. We assume that the reaction might be initiated by the Pd/C-catalyzed reaction of 1 a coupling with a terminal acetylene to afford the intermediate 3 aa, followed by the sequential activation of alkyne by acid species to form the complex E-2.…”

Metal‐Free TFA‐Promoted Regioselective (Hetero)Arylation: Synthesis of (Hetero)Aryl Substituted and Carbazole/Oxepine Fused N‐Heterocycles

“…Based on the previous reports and our experimental observations, a plausible mechanism is outlined in Scheme 4. [21] The reaction could involve initial complexation of azomethine nitrogen [À C(Cl)=NÀ ] of 1 a with TFA to give E-1, then nucleophilic attack at the adjacent chlorine bearing carbon by the C-3 center of the indole 2 c to give E-2, which on release of HCl and TFA to afford desired product 3 ac.…”