Julián Rodríguez-López

A novel, general, totally stereoselective one-pot synthesis of cis-3-substituted 4-formylazetidin-2-ones

A general, totally stereoselective one-pot synthesis of cis-3-substituted-4-formylazetidin-2-ones based upon the reaction of acid chlorides and 1,4-bis-(4-methoxyphenyl)-1,4-diazabuta-1,3-diene, as synthetic equivalent of the corresponding unknown α—formylimine, has been developed.

Synthesis of novel functionalized monocyclic 2-azetidinones from N,N'-diaryl-α-diimines and lithium ester enolates

Abstract Reaction of the glyoxal diimine 1a with lithium ester enolates 2a-b gave 4-imino-2-azetidinones 3a-c in excellent yields. The biacetyl diimine 1b only reacted with the enolate 2a to yield the 4-imino-2-azetidinone 3d and the 5-methylene-2-pyrrolinone 8 depending on the experimental conditions. In addition, various reactions of compounds 3 and of some derivatives, including two new examples of intramolecular β-lactam ring-opening, are described and discussed.

A novel synthetic approach to α-alkylidene-α-lactams

Abstract A simple strategy for the synthesis of various α-alkylidene-β-lactams 4 based upon the condensation between lithium enolates of 3-( N,N -dialkylamino)esters and imines followed by straightforward deamination of the resulting 3-aminoalkyl-β-lactams 3 is outlined. The synthesis of α-alkylidene-β-formyl-β-lactams is a particularly significant feature of this work.

Reaction of N-trimethylsilyl benzil monoimine with simple lithium ester enolates. A synthetic tool for the regioselective one-pot preparation of novel polyfunctional pyrrolines

Sequential treatment of benzil with lithium hexarnethyldisilylamide and simple α-lithiated esters leads, in a regioselective one-pot process, to the polyfunctional pyrrolines(4)–(8), depending on the nature of the enolate and on the experimental conditions. A reasonable explanation for the observed results is discussed. In addition, the reaction of 2,5-dihydro-5-hydroxy-4,5-diphenyl-2-oxo-1H-pyrrole-3-carbonitrile with sodium hydroxide has been reinvestigated and the structure of the previously described product corrected.

The asymmetric synthesis of novel tin-functionalized carbapenam systems through radical cyclization of enyne β-lactams

Abstract New chiral, non-racemic, vinylstannyl carbapenams 2 are easily accessible by the regio- and stereocontrolled tin-mediated, vinyl radical intramolecular cyclization of enyne β-lactams 1 .

Regiocontrolled addition in the reaction of N-(α-methoxyphenacyl)anilines with methyl lithioisobutyrate

Abstract Reaction of various para -substituted N -(α-methoxyphenacyl)anilines with lithio iso butyrate in excess gives,in good yield, compounds 2 - 6 through a regiocontrolled process.

Regiocontrolled nucleophilic additlon to the carbonyl and imino groups in the reaction of 2-arylamino-2-methoxy-1-phenylethanones with simple lithium ester enolates

Abstract The nucleophilic addition of lithium ester enolates 3 to 2-arylamino-2-methoxy-1-phenylethanones I (synthetic equivalents of the related phenylglyoxal anils 2) Is reported. While enolates derived from α,α-dialkyl methyl esters, 3a and 3b, give addition products by attack at either the carbonyl (kinetic products) or the imino groups through a thermally controlled process, those derived from methyl dimethoxyacetate, methyl acetate and methyl propionate, 3c, 3d, and 3e. respectively, only lead to addition products to the carbonyl group. On the basis of the Isolation of all these compounds as stable products and of some transformations and crossover experiments a reasonable mechanism Is proposed for the whole process. In all cases, addition products at the imino groups can also be obtained by the SiO2-catalyzed rearrangement of the corresponding kinetic addition compounds. The synthesis of some substituted 4-benzoyl-β-lactams 8a-g Is a particularly significant feature of this work.