Alejandra G. Suárez

An efficient microwave-assisted green transformation of cellulose into levoglucosenone. Advantages of the use of an experimental design approach

The microwave-assisted pyrolysis of cellulose towards its conversion into levoglucosenone is reported. An experimental design approach was used to find the variables involved in this transformation. Using this approach we established the optimal conditions to obtain the maximum yield of product.

1,3-Dipolar cycloaddition reactions of azomethine ylides with a cellulose-derived chiral enone. A novel route for organocatalysts development.

Cellulose-derived chiral pyrrolidines were synthesized in excellent yields, regioselectivities, and stereoselectivities via a 1,3-dipolar cycloaddition reaction between levoglucosenone and azomethine ylides. An unprecedented isomerization event led to a new family of pyrrolidines with an unusual relative stereochemistry. Preliminary results showed that these compounds are promising organocatalysts for iminium ion-based asymmetric Diels-Alder reactions.

π-Stacking Effect on Levoglucosenone Derived Internal Chiral Auxiliaries. A Case of Complete Enantioselectivity Inversion on the Diels−Alder Reaction

Detailed quantum chemical calculations, experimental evidence, and NMR data rationalize the participation of pi-stacking interaction in the highly asymmetric Diels-Alder reaction using levoglucosenone derived internal chiral auxiliaries, including the appealing effect of inversion of the enantioselectivity by coordination of the substrate with Et 2AlCl.

Cellulose recycling as a source of raw chirality

Modern organic chemistry requires easily obtainable chiral building blocks that show high chemical versatility for their application in the synthesis of enantiopure compounds. Biomass has been demonstrated to be a widely available raw material that represents the only abundant source of renewable organic carbon. Through the pyrolitic conversion of cellulose or cellulose-containing materials it is possible to produce levoglucosenone, a highly functionalized chiral structure. This compound has been innovatively used as a template for the synthesis of key intermediates of biologically active products and for the preparation of chiral auxiliaries, catalysts, and organocatalysts for their application in asymmetric synthesis.

AlCl3DMA reagent in the regioselective solvent free Friedel-Crafts acylation reaction of benzodioxin derivatives

Abstract A general method for the regioselective solvent free Friedel-Crafts acylation of 2-substituted-1,4-benzodioxin derivatives in excellent yields employing the AlCl 3 DMA reagent with acyl halides or anhydrides as acylating agents is described. The acylation of 2-substituted-1,4-benzodioxin derivatives provides the 6-acyl compound as the major product. However, the saturated analogs affords the 7-acyl regioisomer as the main compound.

Regioselective Acylation of Benzodioxin Derivatives Employing AlCl3-DMSO or AlCl3-DMF Reagent in the Friedel-Crafts Reaction

Abstract A Simple and efficient route to the regioselective acylation of benzodioxin derivatives using AICI3-DMSO or AICI3-DMF as reagent with acyl halides and anhydrides is described.

Experimental and theoretical study of a Diels–Alder reaction between a sugar-derived nitroalkene and cyclopentadiene

The Diels-Alder reaction of a pyranose-derived nitroalkene 1 with cyclopentadiene is described, and the unexpected facial selectivity of the cycloaddition is analyzed by a computational study.

Synthesis of tri-O-acetyl-D-allal from levoglucosenone.

Tri-O-acetyl-D-allal has been enantiospecifically synthesized in six steps from levoglucosenone in 55% overall yield. A key step in the synthesis is the anhydro bridge ring-opening with concomitant formation of a 1,3-oxathiolane-2-thione ring.

Fuentes alternativas de materia prima

Alternative sources of starting materials Biomass is the source of renewable carbon that will allow to achieve the future development of our society. With the prospect of the fossil resources depletion, it is necessary to find new alternative sources of energy and raw materials. Chemistry will play a key role to design new materials from biomass which will reshape our way of living and consumption.

Neighboring-group participation in benzylidene acetal ring-opening of a 2-cyano-2-deoxypyranoside derivative by diethylaluminum cyanide

The oxirane ring-opening of an anhydro sugar with diethylaluminum cyanide (Et(2)AlCN) is a direct approach for obtaining a cyano derivative. Methyl 2,3-anhydro-4,6-O-benzylidene-alpha-D-allopyranoside showed anomalous chemical behavior when treated with Et(2)AlCN. The reaction afforded the corresponding beta-cyanohydrin as the minor component from a mixture of compounds resulting from the benzylidene acetal ring-opening caused by the attack of ethyl or cyano groups.