Azotides as Modular Peptide-Based Ligands for Asymmetric Lewis Acid Catalysis
Synthesis of azotides and evaluation of these as ligands for enantioselective Lewis acid catalysis is reported. The ligands were readily prepared from the chiral pool of amino acids and perform well in the cobalt(II)-catalyzed formation of asymmetric hete
Jacobsen, Christian Borch,Nielsen, Daniel Steen,Meldal, Morten,Diness, Frederik
p. 6940 - 6945
(2019/06/10)
Control of selectivity in the generation and reactions of oxonium ylides
Dirhodium catalyzed reactions of aryl-substituted tetrahydropyranone diazoacetoacetates produce ylide intermediates that unexpectedly yield two oxabicyclo[4.2.1]-nonane diastereoisomers, but a single diastereoisomer is formed by increasing the steric bulk of the aryl substituent.
Jaber, Deana M.,Burgin, Ryan N.,Hepler, Matthew,Zavalij, Peter,Doyle, Michael P.
supporting information; experimental part
p. 7623 - 7625
(2011/09/12)
Heterogeneous Lewis acid catalysis with self-organized polymeric rare earth arylsulfonates under solvent-free conditions
Polymeric rare earth arylsulfonates, easily prepared from rare earth triisopropoxides and biphenyl-4,4'-disulfonic acid (BPDSA) or 1,3,5-triphenylbenzene trisulfonic acid (TPTSA) in a self-organization manner, were found to work as an efficient heterogene
Efficient organocatalysis with a calix[4]pyrrole derivative
The 10α,20β-bis(4-nitrophenyl)-calix[4]pyrrole was found to act as an effective organocatalyst for the hetero Diels-Alder reaction of Danishefsky's diene with aromatic aldehydes. This discovery is the first reported case of a calixpyrrole that exhibits or
Cafeo, Grazia,De Rosa, Margherita,Kohnke, Franz H.,Neri, Placido,Soriente, Annunziata,Valenti, Luca
p. 153 - 155
(2008/04/13)
Hetero-diels-alder reaction catalyzed by self-organized polymeric rare earth complexes under solvent-free conditions
-2-Substituted 2,3-dihydropyran-4-one derivatives were conveniently synthesized under solvent-free conditions by Lewis acid-catalysis with a polymeric scandium sulfonate complex, which can be prepared in a self-organized manner in one step and successfull
Stereoselectivity in metal carbene and Lewis acid-catalyzed reactions from diastereomeric dirhodium(II) carboxamidates: Menthyl N-acetyl-2- oxoimidazolidine-4(S)-carboxylates
The influence of a chiral menthyl group as the pendant ester substituent on the N-acetyl-2-oxoimidazolidine-4S-carboxylate ligands in chiral dirhodium(II) imidazolidinone catalysts has been examined. Significant match/mismatch influences are evident in the observed stereocontrol for carbon-hydrogen insertion reactions with diazoacetates, but these effects are minimal in cyclopropanation reactions. Steric restrictions prevent effective enantiocontrol in hetero-Diels-Alder reactions using these menthyl-substituted catalysts.
Doyle, Michael P.,Morgan, John P.,Colyer, John T.
p. 5525 - 5532
(2007/10/03)
Dramatically synergetic effect of carboxylic acid additive on tridentate titanium catalyzed enantioselective hetero-Diels - Alder reaction: Additive acceleration and nonlinear effect
This paper describes the successful development of a group of highly efficient chiral tridentate titanium catalysts for hetero-Diels -Alder reaction of Danishefsky's diene and a variety of aldehydes through ligand and additive diversity. Dramatically syne
Yuan, Yu,Long, Jiang,Sun, Jie,Ding, Kuiling
p. 5033 - 5042
(2007/10/03)
Optically active cationic cobalt(III) complexes: Highly efficient catalysts for enantioselective hetero Diels-Alder reaction
Optically active β-ketoiminato cobalt(III) complexes were developed for use as effective catalysts of the enantioselective hetero Diels-Alder reaction of aryl and alkyl aldehydes with 1-methoxy-[3-(tert-butyldimethylsilyl)oxy]-1,3-butadiene. In the presen