Jesús Joglar

Casuarine Stereoisomers from Achiral Substrates: Chemoenzymatic Synthesis and Inhibitory Properties

A straightforward chemoenzymatic synthesis of four uncovered casuarine stereoisomers is described. The strategy consists of L-fuculose-1-phosphate aldolase F131A-variant-catalyzed aldol addition of dihydroxyacetone phosphate to aldehyde derivatives of 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and its enantiomer (LAB) and subsequent one-pot catalytic deprotection-reductive amination. DAB and LAB were obtained from dihydroxyacetone and aminoethanol using D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase catalysts, respectively. The new ent-3-epi-casuarine is a strong inhibitor of α-d-glucosidase from rice and of rat intestinal sucrase.

Stereoselective Syntheses of Allylic Amines Through Reduction of 1-Azadiene Intermediates

Abstract The stereoselective synthesis of primary and secondary E-allylic amines by reduction of 1-azadiene intermediates is described. β-Enamino phosphonium salts are suitable starting materials to prepare secondary allylic amines. Two methods are reported for the obtention of primary allylic amines from 4-amino-1-aza-1,3-dienes. Method A leads to the desired compounds by straight reduction with AlH3 or DIBALH; method B is a stepwise procedure that allows for better yields when sterically hindered 4-amino-1-aza-1,3-dienes are employed.

Reduction of 5,6-dihydro-2H-1,3-oxazines. A simple approach to 1,3-aminoalcohols from 2-aza-1,3-dienes

Abstract The reduction of 5,6-dihydro-2 H -1,3-oxazines 2 is described for the first time. This reaction allows the diastereoselective synthesis of 1,3-amino alcohols 3 and 4 with three and four chiral centers.

Synthesis and NMR configurational study of imidazo[2,1-b]thiazoles from 1H-1,4-diazepine-7(6H)-thiones

Abstract A thermal intramolecular cyclization of 1-vinyl2,3-dihydro-3 H -imidazole-2-thiones to imidazo[2,1-b]thiazoles is reported. A heteronuclear correlation study of these systems was made in order to establish the configuration of the products.

A simple stereoselective synthesis of primary allylic amines from 4-amino-1-azadienes

A new and efficient synthesis of primary allylic amines (2) from 4-amino-1-azadines (1)via 1-azadienes (5) by reduction processes is described; the process is very simple, highly stereoselective, and takes place with very high chemical yields.

Silylation of 2-Aza-1,3-dienes. The first example of a thermally stable N-trimethyl-silyldivinylamine

N-Trimethylsilyldivinylamines were synthesized in a highly stereoselective manner by reaction of 2-aza-1,3-dienes with trimethylsilyl trifluoromethanesulphonate.