Palladium-Catalyzed Regioselective Arylation of Unprotected Allylamines

Abstract

Palladium-catalyzed organometallic transformations of free amines are often unsuccessful due to side reactions, such as oxidation, that can occur. However, the ability to furnish the free amine products from these reactions is important for improving the utility and sustainability of these processes, especially for accessing their potential as medicinal and agrochemical agents. Notably, the 3,3-diarylallylamine motif is prevalent in a variety of biologically relevant structures, yet there are few catalytic approaches to their synthesis, and none involving the free amine. Herein, we describe a simple protocol for the arylation of cinnamylamines and the diarylation of terminal allylamines to generate a diverse group of 3,3-diarylallylamine products using a Pd II precatalyst. Key features of the method are the ability to access relatively mild conditions that facilitate a broad substrate scope as well as direct diarylation of terminal allylamine substrates. In addition, several complex and therapeutically relevant molecules are included to demonstrate the utility of the transformation.

A Zn(ii)-functionalized COF as a recyclable catalyst for the sustainable synthesis of cyclic carbonates and cyclic carbamates from atmospheric CO2

“…Based on previous work, 69 the tentative mechanism was proposed for the Zn@TpTta-catalyzed cyclization of allylamine to afford the corresponding cyclic carbonate in the presence of NIS and CO 2 (Fig. 9).…”

“…Inspired by previous reports, 69,72 we have attempted the carbon dioxide-incorporated cyclization reaction of some selected unsaturated amine systems with a Zn( ii )-containing COF under solvent-free conditions. To investigate the strategy, we attempted to accomplish the goal by the treatment of a typical allylamine system with NIS (equimolar quantity) under exposure to 1 atm CO 2 without using any of these solvents ( e.g.…”

“…of t -BuOI were sufficient to form the corresponding products in moderate yields owing to the existence of an exceptionally substrate-favoured equilibrium between two components: allyl alcohols/CO 2 and (allyl)OC(O)OH (Scheme 4). As an instance of the sequential introduction of CO 2 and a halogen species, the iodo-cyclization reaction of unsaturated amine systems 69 and CO 2 molecules with t -BuOI was established earlier, 69 a but the satisfactory levels of the substrate transformations into the corresponding products and exploration of the substrate scope have not been reported to date.…”

Chiral Hypervalent Iodine Catalysis Enables an Unusual Regiodivergent Intermolecular Olefin Aminooxygenation

“…We thank Dr. Michael C. Young (University of Toledo) for helpful discussions based on his recent work. 92 The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.…”

Alkene Difunctionalization Directed by Free Amines: Diamine Synthesis via Nickel-Catalyzed 1,2-Carboamination

“…[11] Furthermore, free amines often bind strongly to the transition metal catalyst and sequester it off cycle. [12] While important precedents have demonstrated the ability of free amines to direct catalytic hydrofunctionalization, [13,14] Heck-type coupling, [15] and homodiarylation, [16] three-component functionalization of free amines remains unknown to the best of our knowledge.…”