Ghosh, Avipsa published the artcileCoupling Catalytic Alkene Hydroacylation and α-Arylation: Enantioselective Synthesis of Heterocyclic Ketones with α-Chiral Quaternary Stereocenters, Safety of 5-Fluoro-1H-indole-2-carbaldehyde, the publication is ACS Catalysis (2016), 6(4), 2673-2680, database is CAplus.
We report a strategy that combines alkene hydroacylation and enantioselective α-(hetero)arylation reactions to form a wide variety of nitrogen-containing heterocyclic ketones bearing α-chiral quaternary stereogenic centers. Exo-selective, intramol. Ni-catalyzed hydroacylations of N-homoallylindole- and N-homoallylpyrrole-2-carboxaldehydes form α-substituted six-membered heterocyclic ketones in up to 95% yield, while N-heterocyclic carbene (NHC) catalyzed hydroacylations of N-allylindole- and N-allylpyrrole-2-carboxaldehydes form α-substituted five-membered heterocyclic ketones in up to 99% yield. The racemic five- and six-membered products of Ni- and NHC-catalyzed hydroacylation reactions are readily transformed into heterocyclic ketones containing an α-chiral quaternary stereogenic center by enantioselective Ni-catalyzed α-arylation and α-heteroarylation reactions. The chiral, nonracemic products formed through a combination of alkene hydroacylation and α-(hetero)arylation reactions are formed in moderate to high yields (44-99%) with excellent enantioselectivities (typically >95% ee). The identity of the precatalyst for Ni-catalyzed α-(hetero)arylation is dictated by the identity of the α-substituted heterocyclic ketone starting material. α-(Hetero)arylations of six-membered heterocyclic ketones occur at 65-85 °C in the presence of a catalyst generated in situ from Ni(COD)2 and (R)-BINAP or (R)-DIFLUORPHOS. α-(Hetero)arylation of five-membered heterocyclic ketones must be conducted at room temperature in the presence of an [((R)-BINAP)Ni(η2-NC-Ph)] precatalyst or a catalyst generated in situ from Ni(COD)2, (R)-DIFLUORPHOS, and benzonitrile.
ACS Catalysis published new progress about 220943-23-7. 220943-23-7 belongs to indole-building-block, auxiliary class Indole,Fluoride,Aldehyde, name is 5-Fluoro-1H-indole-2-carbaldehyde, and the molecular formula is C9H6FNO, Safety of 5-Fluoro-1H-indole-2-carbaldehyde.
Referemce:
https://www.nature.com/articles/s41429-020-0333-2,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles