Intermolecular reactions of electron-rich heterocycles with copper and rhodium carbenoids.

Intermolecular reactions of electron-rich heterocycles with copper and rhodium carbenoids.

Chemical Society reviews (2007-06-20)

Huw M L Davies, Simon J Hedley

ABSTRACT

This tutorial review describes the reactions of the electron-rich heterocycles pyrrole, furan, indole and benzofuran with copper and rhodium carbenoids. Two main reaction pathways are possible, involving either a concerted non-synchronous cyclopropanation or zwitterionic intermediates. A diverse range of products are possible and the outcome is very dependent on the structure of the heterocycle and the carbenoid. To emphasize this point the carbenoids are considered in terms of three classes: acceptor, acceptor-acceptor and donor-acceptor carbenoids. Unusual catalytic asymmetric transformations can be achieved with this chemistry while the asymmetric induction is strongly influenced by how the carbenoid can approach the heterocycles. This tutorial review gives an overview of the general features that govern the chemistry of metal carbenoids with heterocycles and presents a mechanistic rationale for the range of products that can be formed.

MATERIALS

Product Number

Brand

Product Description

204218

Sigma-Aldrich

Rhodium, powder, 99.95% trace metals basis

GF24911726

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

GF22634120

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

GF44569907

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

GF49946417

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

GF36379345

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

GF49036204

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

GF15499413

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

GF14938005

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

GF87742659

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

GF57675561

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

GF82366342

Rhodium, foil, not light tested, 50x50mm, thickness 0.00025mm, permanent polyester support, 99.9%

GF54466937

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

GF64213680

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

GF12568013

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

GF40539405

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

GF45819995

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

GF96356559

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

GF71687357

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

GF04978963

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

GF72510364

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

GF33789550

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

GF26710680

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

GF83497652

Rhodium, wire reel, 0.05m, diameter 1.0mm, as drawn, 99.9%

GF74452316

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

GF35442727

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

GF80841146

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

GF17514312

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

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%