Homologation of Electron-Rich Benzyl Bromide Derivatives via Diazo C–C Bond Insertion
作者:Atanu Modak、Juan V. Alegre-Requena、Louis de Lescure、Kathryn J. Rynders、Robert S. Paton、Nicholas J. Race
DOI:10.1021/jacs.1c11503
日期:2022.1.12
The ability to manipulate C–C bonds for selective chemical transformations is challenging and represents a growing area of research. Here, we report a formal insertion of diazo compounds into the “unactivated” C–C bond of benzyl bromide derivativescatalyzed by a simple Lewisacid. The homologation reaction proceeds via the intermediacy of a phenonium ion, and the products contain benzylic quaternary
A decarboxylativeintramolecularaziridination reaction of alkene‐tethered 4H‐isoxazol‐5‐ones with a palladium/phosphine catalyst gave 1‐azabicyclo[3.1.0]hex‐2‐enes in moderate to high yields (see scheme; dba=dibenzylideneacetone). The resulting N‐fused bicyclic aziridines readily reacted with various reagents to afford ring‐opening pyrroline derivatives.
A dual platinum‐ and pyrrolidine‐catalyzed direct allylic alkylation of allylic alcohols with various activemethylenecompounds to produce products with high monoallylation selectivity was developed. The use of pyrrolidine and acetic acid was essential, not only for preventing undesirable side reactions, but also for obtaining high monoallylation selectivity.
ORGANOMETALLIC RUTHENIUM COMPLEXES AND RELATED METHODS FOR THE PREPARATION OF TETRA-SUBSTITUTED AND OTHER HINDERED OLEFINS
申请人:BERLIN Jacob
公开号:US20120123133A1
公开(公告)日:2012-05-17
The invention relates to ruthenium alkylidene complexes having an N-heterocyclic carbene ligand comprising a 5-membered heterocyclic ring having a carbenic carbon atom and at least one nitrogen atom contained within the 5-membered heterocyclic ring, wherein the nitrogen atom is directly attached to the carbenic carbon atom and is substituted by a phenyl ring, and wherein the phenyl ring has a hydrogen at either or both ortho positions and is substituted at at least one ortho or meta position. The invention also relates to an olefin metathesis reactions and particularly to the preparation of tetra-substituted cyclic olefins via a ring-closing metathesis.