Synthesis of indolizidines from optically pure α-amino acids via stereocontrolled rhodium-catalyzed hydroformylation of N-allylpyrroles.

Synthesis of indolizidines from optically pure α-amino acids via stereocontrolled rhodium-catalyzed hydroformylation of N-allylpyrroles.

Chirality (2011-08-23)

Raffaello Lazzaroni, Roberta Settambolo

ABSTRACT

Indolizidine alkaloids have attracted considerable attention because of their vast array of structural diversity and varied biological activity. This article relates the results that we obtained in the field of the total synthesis of indolizidines from α-amino acids, based on the rhodium-catalyzed hydroformylation of N-allylpyrroles intermediates. The formed pyrrolylbutanals undergo an intramolecular cyclodehydration to 5,6-dihydroindolizines, which are fully hydrogenated to indolizidines. All reaction sequences are stereocontrolled: indeed, the chiral center in the starting amino acid is transferred into 5,6-dihydroindolizine moiety with complete stereochemical integrity and the new stereogenic center at C9 carbon atom in the final indolizidines is generated in only one configuration.

MATERIALI

N° Catalogo

Marchio

Descrizione del prodotto

204218

Sigma-Aldrich

Rhodium, powder, 99.95% trace metals basis

GF74452316

Rhodium, wire reel, 0.05m, diameter 0.5mm, as drawn, 99.9%

GF80841146

Rhodium, foil, 25x25mm, thickness 0.15mm, as rolled, 99.9%

GF57675561

Rhodium, foil, light tested, 25x25mm, thickness 0.05mm, as rolled, 99.9%

GF44569907

Rhodium, foil, 25x25mm, thickness 0.125mm, as rolled, 99.9%

GF72510364

Rhodium, wire reel, 0.5m, diameter 0.25mm, hard, 99.9%

GF14938005

Rhodium, microfoil, disks, 25mm, thinness 0.1μm, specific density 124μg/cm², permanent mylar 3.5μm support, 99.9%

GF45819995

Rhodium, wire reel, 0.05m, diameter 0.25mm, hard, 99.9%

GF40539405

Rhodium, foil, 25x25mm, thickness 0.1mm, as rolled, 99.9%

GF49946417

Rhodium, microfoil, disks, 10mm, thinness 0.50μm, specific density 620μg/cm², permanent mylar 3.5μm support, 99.99%

GF71687357

Rhodium, microfoil, disks, 10mm, thinness 0.1μm, specific density 124μg/cm², permanent mylar 3.5μm support, 99.9%

GF06539979

Rhodium, wire reel, 0.1m, diameter 0.5mm, as drawn, 99.9%

GF12568013

Rhodium, foil, light tested, 25x25mm, thickness 0.05mm, as rolled, x-ray quality, 99.9%

GF35442727

Rhodium, foil, not light tested, 25x25mm, thickness 0.0005mm, permanent polyester support, 99.85%

GF04978963

Rhodium, foil, not light tested, 10x10mm, thickness 0.012mm, as rolled, 99.9%

GF49036204

Rhodium, foil, not light tested, 25x25mm, thickness 0.00075mm, permanent polyester support, 99.85%

GF96356559

Rhodium, foil, light tested, 25x25mm, thickness 0.075mm, as rolled, 99.9%

GF87742659

Rhodium, foil, not light tested, 25x25mm, thickness 0.001mm, permanent polyester support, 99.85%

GF22634120

Rhodium, foil, not light tested, 50x50mm, thickness 0.00075mm, permanent polyester support, 99.85%

GF27499045

Rhodium, wire reel, 0.1m, diameter 0.25mm, hard, 99.9%

GF37207166

Rhodium, wire reel, 0.1m, diameter 1.0mm, as drawn, 99.9%

GF36379345

Rhodium, foil, light tested, 15x15mm, thickness 0.05mm, as rolled, 99.9%

GF64213680

Rhodium, wire reel, 0.05m, diameter 0.12mm, as drawn, 99.9%

GF24911726

Rhodium, foil, not light tested, 25x25mm, thickness 0.012mm, as rolled, 99.9%

GF33789550

Rhodium, foil, not light tested, 50x50mm, thickness 0.001mm, permanent polyester support, 99.85%

GF38835737

Rhodium, wire reel, 0.2m, diameter 0.12mm, as drawn, 99.9%

GF37380089

Rhodium, wire reel, 0.2m, diameter 0.25mm, hard, 99.9%

GF17496973

Rhodium, wire reel, 0.2m, diameter 0.5mm, as drawn, 99.9%

GF54466937

Rhodium, wire reel, 0.5m, diameter 0.12mm, as drawn, 99.9%

GF17514312

Rhodium, foil, not light tested, 25x25mm, thickness 0.00025mm, permanent polyester support, 99.9%