Catalytic and regioselective acylation of aromatic heterocycles using carbon monoxide and olefins

An Efficient and General Iron‐Catalyzed Arylation of Benzyl Alcohols and Benzyl Carboxylates

“…Hence, the development of environmentally benign C À C coupling reactions of arenes is an important topic of organometallic chemistry and catalysis. Elegant examples of direct CÀH transformations of arenes [1] include the addition of olefins to acetophenones (Murai reaction) [2] and aromatic imines, [3] novel additions of olefins to electronrich arenes [4] and heterocycles, [5] the addition of aromatics to alkynes, [6] the carbonylation of heterocycles, [7] and the cyclization of arene-alkyne substrates [8] as well as the C-arylation of heteroarenes. [9] In addition, recently significant progress has been seen in Friedel-Crafts-like alkylations [10] in which the use of lanthanide and actinide triflates [11] as well as heterogeneous catalysts [12] is especially noteworthy.…”

New Synthesis of Furans: the Rhodium‐Catalysed Carbonylative Addition of Arylboronic Acids to Propargylic Alcohols/ Cyclisation Sequence

“…Although carbon monoxide has been widely used to prepare various stoichiometric organometallic acylation reagents, catalytic carbonylative hydroacylation reactions of unsaturated compounds are rather uncommon. The earlier examples deal with C À H activation of benzene with rhodium precursors, [4] pyridines [5] and imidazoles [6] with ruthenium clusters. Under CO pressure, the thus obtained metal acyl derivatives are reacted with olefins for ketone synthesis.…”

Synthesewege zu N‐heterocyclischen Carbenkomplexen: Pyridin‐Carben‐Tautomerisierungen

“…metallvermittelten oder -katalysierten Reaktionen aufgezeigt. In [Ru 3 (CO) 12 ]-katalysierten C-C-Kreuzkupplungen, die unter C-H-Aktivierung von beispielsweise Pyridinderivaten verlaufen, [15] wurden Hydridovinylkomplexe als Intermediate isoliert. Im Licht der Pyridin-Carben-Tautomerisierung ist es durchaus denkbar, dass Carbene auch in dieser Reaktion eine Rolle spielen.…”