Sequential Cross‐Coupling/Annulation of ortho‐Vinyl Bromobenzenes with Aromatic Bromides for the Synthesis of Polycyclic Aromatic Compounds

Abstract

As equential cross-coupling/annulation of orthovinyl bromobenzenes with aromatic bromides was realized, providing adirect and modular approach to access polycyclic aromatic compounds.Avinyl-coordinated palladacycle was proposed as the key intermediate for this sequential process. Excellent chemoselectivity and regioselectivity were observed in this transformation. The practicability of this method is highlighted by its broad substrate scope,e xcellent functional group tolerance,a nd rich transformations associated with the obtained products.

Carbonyl Olefin Metathesis and Dehydrogenative Cyclization of Aromatic Ketones and gem‐Difluoroalkenes

“…In this context, the development of synthesis of phenanthrene derivatives through one‐pot cascade reactions of readily available starting materials is of great value, because these compounds containing conjugated π‐systems have increasing applications in drug design and material development [9–14] . Among early developed methods for the synthesis of phenanthrenes, [15–39] the Scholl‐type oxidation reactions with stilbenes as substrates are the most widely used [25–29] . But these reactions usually require excessive strong acids and/or strong oxidants, thus resulting in unwanted side reactions and inseparable byproducts, leading to low reaction efficiency (Scheme 1b) [25–29] .…”

Suzuki-Miyaura Coupling Enabled by Aryl to Vinyl 1,4-Palladium Migration

“…The ortho-vinyl arylbromides (1a-1e, 1g-1v, 1B) (Wei et al, 2019;Wei et al, 2018;Ryutaro Hayashi, 2018;Shen et al, 2017;Rossi et al, 2001), (hetero)aryl boronate esters (2a-2h, 2l-2o, 2q, 5a-5c, 5j, 5r) (Zhang et al, 2018;Carreira-Barral et al, 2018;Zhou et al, 2017;Ranjani and Nagarajan, 2017;Bello and Schmidt-Leithoff, 2012;Yu et al, 2010;Gómez-Blanco et al, 2009;Iwai et al, 2008;Stephen J. Baker, 2006;Burstein et al, 2005;Wong et al, 2002), diaryl-vinyl boronate esters (7h, 7i) were prepared according to the literatures. Heteroaryl boronate esters (5g-5h, 5m-5q) and vinyl boronate esters (7a-7g) were purchased and used directly from commercial sources.…”