Organic chemistry. Rh-catalyzed C-C bond cleavage by transfer hydroformylation.

Organic chemistry. Rh-catalyzed C-C bond cleavage by transfer hydroformylation.

Science (New York, N.Y.) (2015-01-03)

Stephen K Murphy, Jung-Woo Park, Faben A Cruz, Vy M Dong

ABSTRACT

The dehydroformylation of aldehydes to generate olefins occurs during the biosynthesis of various sterols, including cholesterol in humans. Here, we implement a synthetic version that features the transfer of a formyl group and hydride from an aldehyde substrate to a strained olefin acceptor. A Rhodium (Xantphos)(benzoate) catalyst activates aldehyde carbon-hydrogen (C-H) bonds with high chemoselectivity to trigger carbon-carbon (C-C) bond cleavage and generate olefins at low loadings (0.3 to 2 mole percent) and temperatures (22° to 80°C). This mild protocol can be applied to various natural products and was used to achieve a three-step synthesis of (+)-yohimbenone. A study of the mechanism reveals that the benzoate counterion acts as a proton shuttle to enable transfer hydroformylation.

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%

GF40539405

Rhodium, foil, 25x25mm, thickness 0.1mm, 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%

GF45819995

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

GF06539979

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

GF37207166

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

GF35442727

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

GF71687357

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

GF49946417

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

GF14938005

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

GF64213680

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

GF04978963

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

GF22634120

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

GF12568013

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

GF96356559

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

GF49036204

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

GF87742659

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

GF33789550

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

GF27499045

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

GF17496973

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

GF15499413

Rhodium, foil, not light tested, 25x25mm, thickness 0.006mm, as rolled, 99.9%

GF24911726

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

GF26710680

Rhodium, wire reel, 0.1m, diameter 0.12mm, as drawn, 99.9%

GF37380089

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

GF36379345

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

GF38835737

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