discovery of the oxazolidone derivative as a novel scaffold for NAAAinhibitors, and studied the structure–activity relationship (SAR) by modification of the side chain and terminal lipophilic substituents. The results showed that the link chain length of C5, straight and saturated linkages were the preferred shape patterns for NAAA inhibition. Several nanomolar NAAAinhibitors were described, including
The Stereochemical Course of Intramolecular Michael Reactions
作者:Eugene E. Kwan、Jonathan R. Scheerer、David A. Evans
DOI:10.1021/jo302138z
日期:2013.1.4
We present a general model for understanding the stereochemicalcourse of intramolecular Michael reactions. We show that the addition of β-ketoester enolates to α,β-unsaturated esters and imides bearing adjacent stereocenters (X, Y = H, Me, OR) leads to high levels of asymmetric induction. Reinforcing and nonreinforcing stereochemical relationships are evaluated from the syn and anti reactant diastereomers
Synthesis of Spirocyclic Indolines by Interruption of the Bischler–Napieralski Reaction
作者:Jonathan William Medley、Mohammad Movassaghi
DOI:10.1021/ol401465y
日期:2013.7.19
The development of a versatile method for the synthesis of spirocyclic pyrrolidinoindolines is discussed. Treatment of N-acyltryptamines with trifluoromethanesulfonic anhydride–2-chloropyridine reagent combination affords highly persistent spiroindoleninium ions that are subject to intra- and intermolecular addition at C2 by nucleophiles.
New cephalosporin compounds of the formula: ##STR1## wherein R.sub.1 is hydrogen or hydroxy, R.sub.2 is a substituted alkanoyl group, R.sub.3 is hydrogen, carbamoyloxy, alkanoyloxy or a heterocyclic-thio group which may have suitable substituents, and R.sub.4 is carboxy or protected carboxy.
Catalytic Enantioselective Amination of Enolsilanes Using <i>C</i><i><sub>2</sub></i>-Symmetric Copper(II) Complexes as Chiral Lewis Acids
作者:David A. Evans、Douglas S. Johnson
DOI:10.1021/ol990113r
日期:1999.8.1
[formula: see text] [Cu(S,S)-t-Bu-box](OTf)2 (1) catalyzes the enantioselective amination of enolsilanes with azodicarboxylate derivatives. Isomerically pure enolsilanes of aryl ketones, acylpyrroles, and thioesters added to the azo-imide in greater than 95% ee. The use of an alcohol additive was critical to achieving catalyst turnover.