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Steric and Electronic Requirements in the Synthesis of 2,3‐Dihydro‐4(1 H )‐quinolinones by the Tandem Michael‐S N Ar Reaction
Author(s) -
Bunce Richard A.,
Nago Takahiro,
Abuskhuna Suaad
Publication year - 2015
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.2142
Subject(s) - chemistry , steric effects , michael reaction , adduct , tandem , nucleophile , acceptor , electronic effect , molecule , electrophilic aromatic substitution , medicinal chemistry , stereochemistry , organic chemistry , catalysis , materials science , physics , composite material , condensed matter physics
The steric and electronic requirements have been investigated for the synthesis of 2,3‐dihydro‐4(1 H )‐quinolinones by the tandem Michael‐S N Ar reaction. Substrates bearing a single methyl group at the β‐enone carbon gave excellent yields of the title compounds from both the E and Z isomers with X═H or NO 2 . Substrates with β,β‐dimethyl substitution at the Michael terminus gave low yields of heterocyclic products in molecules having monoactivated S N Ar aromatic acceptor rings (X═H) and very good yields for diactivated systems (X═NO 2 ). For these hindered substrates, success in the final cyclization hinges on the ability of the aromatic acceptor to capture the pendant nitrogen nucleophile of the initial Michael adduct before this intermediate can revert to starting materials.