Chemistry of sulfones: synthesis of a new chiral nucleophilic catalyst

Dı́ez, David; Gil, María José; Moro, Rosalina F.; Garrido, Narciso M.; Marcos, Isidro S.; Basabe, P.; Sanz, Francisca; Broughton, Howard B.; Urones, Julio G.

doi:10.1016/j.tetasy.2005.08.009

Cited by 26 publications

(5 citation statements)

References 18 publications

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“…A major diastereomer of Ugi product 4a , which can be easily obtained by column chromatography, was utilized as the catalyst in toluene at −60 °C ( Scheme 1 ). The selectivity factor [ 34 ], which was estimated by ee of acetylated product 6 and unreacted alcohol 5 [ 35 ], was indicated to be 2.33. It was noted that the Ugi product 4a was capable of catalyzing the acylation reaction, although the selectivity was not satisfied at the moment.…”

Section: Resultsmentioning

confidence: 99%

Studies on the Synthesis of DMAP Derivatives by Diastereoselective Ugi Reactions

et al. 2011

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Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridine-carboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low diastereoselectivity. On the contrary, reactions with 4-(dimethylamino)-3-pyridine-carboxaldehyde delivered 3-substituted DMAP derivatives with moderate to high diastereoselectivity. The combination of α-amino acid and DMAP-based aldehyde is thus important to achieve high diastereoselectivity. Kinetic resolution of a secondary alcohol using a chiral DMAP derivative obtained through these reactions was also examined.

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Section: Resultsmentioning

confidence: 99%

Studies on the Synthesis of DMAP Derivatives by Diastereoselective Ugi Reactions

et al. 2011

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“…Díez pursued another strategy in order to benefit from the pendant attractive interaction exploited by Yamada. Thus, a series of chiral PPY catalysts containing a sulfone tethered to a pyrrolidine ring was prepared (Scheme ) . Unfortunately, selectivities in the kinetic resolution of (±)-1-phenylethanol were low (<2).…”

Section: 1 Kinetic Resolutions211 Resolutions Of Alcoholsmentioning

confidence: 99%

Chiral Dialkylaminopyridine Catalysts in Asymmetric Synthesis

2007

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“…In this paper we describe our studies on the synthesis of the epimer at C-2 of pyrrolidine 6 , as we are interested in comparing the properties of both diastereoisomers in organocatalytic reactions. In previous studies with PPY-derivatives, we had observed the epimerization of that stereogenic center when it was treated with bases [ 22 ]. Taking this into account, we first tried the epimerization at C-2 in compound 8 , obtained directly from 4 by treatment with benzylamine.…”

Section: Resultsmentioning

confidence: 99%