Rhodium-Catalyzed Coupling Reactions of Arylboronic Acids to Olefins in Aqueous Media

C═N-Containing Azaarenes as Activating Groups in Enantioselective Catalysis

“…Furthermore, Lautens and co-workers had demonstrated that vinylazines are effective acceptors in non-asymmetric rhodium-catalyzed additions of arylboronic acids (Scheme 2). 9 These results suggested that, at least in principle, a catalytic enantioselective variant employing β-monosubstituted alkenylazaarenes might be possible, which would be a useful route to β-stereogenic 2-alkylazaarenes.…”

“…For example, in 2001, Lautens and co-workers described the rhodium-catalyzed addition of arylboronic acids to vinylazines 1 in water, using a rhodium complex containing water-soluble phosphine ligands, in the presence of 0.5 equivalents of sodium dodecyl sulfate (Scheme 2). 9 The scope of the acceptor included 2-vinylpyridine (2a,b), vinylpyrazine (2c), 4-vinylpyridine (2d), and 2-vinylquinoline (2e), and a range of arylboronic acids were effective. In addition, competitive insertion of rhodium into the carbon-bromine bond of 2-bromophenylboronic acid was not observed (2b).…”

Ruthenium Complex-Catalysed Heck Reactions of Areneboronic Acids; Mechanism, Synthesis and Halide Tolerance

“…In a related case, Lautens has shown that either Ar-H addition or formal displacement of vinyl-H by Ar can occur depending on the structure of the reactant. [18] In palladium catalysis, the best precedent is due to Uemura, who showed that arylboronic acids react with alkenes to give the product expected from a Heck reaction. [19] No re-oxidant was reported in this case (adventitious air?)…”

Aerobic Alcohol Oxidation Coupled to Palladium‐Catalyzed Alkene Hydroarylation with Boronic Esters

“…[9] However, we observed catalyst decomposition and competitive initial transmetalation, which generates the oxidative Heck product (4). [10] The poor stability of [Pd{(À)-sparteine}Cl 2 ] under these conditions prompted us to identify a more robust catalyst system.…”