Pentaatomic heteroaromatic cations. 18. Acylation of pyrrole and N-methylpyrrole with 1,3-benzoxathiolium tetrafluoroborates. A high-yield method for the synthesis of diacylpyrroles
Iodide as an Activating Agent for Acid Chlorides in Acylation Reactions
作者:Russell J. Wakeham、James E. Taylor、Steven D. Bull、James A. Morris、Jonathan M. J. Williams
DOI:10.1021/ol400035f
日期:2013.2.1
Acid chlorides can be activated using a simple iodide source to undergo nucleophilic attack from a variety of relatively weak nucleophiles. These include Friedel–Crafts acylation of N-methylpyrroles, N-acylation of sulfonamides, and acylation reactions of hindered phenol derivatives. The reaction is believed to proceed through a transient acidiodide intermediate.
Palladium catalyzed carbonylative generation of potent, pyridine-based acylating electrophiles for the functionalization of arenes to ketones
作者:Yi Liu、Angela M. Kaiser、Bruce A. Arndtsen
DOI:10.1039/d0sc03129a
日期:——
ultimate elimination of a new class of potent Friedel–Crafts acylating agent: N-acyl pyridinium salts. The latter can be exploited to modulate reactivity and selectivity in carbonylative arene functionalization chemistry, and allow the efficient synthesis of ketones with a diverse array of (hetero)arenes.
Friedel−Crafts Acylation of Pyrroles and Indoles using 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) as a Nucleophilic Catalyst
作者:James E. Taylor、Matthew D. Jones、Jonathan M. J. Williams、Steven D. Bull
DOI:10.1021/ol1025348
日期:2010.12.17
1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) has been shown to be an effective catalyst for the regioselective Friedel−Crafts C-acylation of pyrroles and indoles in high yields. A detailed mechanistic study implies that DBN is acting as a nucleophilic organocatalyst, with the X-ray crystal structure of a key N-acyl-amidine intermediate having been determined for the first time.
Reversed-Polarity Synthesis of Diaryl Ketones via Palladium-Catalyzed Cross-Coupling of Acylsilanes
作者:Jason R. Schmink、Shane W. Krska
DOI:10.1021/ja2064318
日期:2011.12.14
Acylsilanes serve as acylanion equivalents in a palladium-catalyzed cross-coupling reaction with aryl bromides to give unsymmetrical diaryl ketones. Water plays a unique and crucial activating role in these reactions. High-throughput experimentation techniques provided successful reaction conditions initially involving phosphites as ligands. Ultimately, 1,3,5,7-tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane