✍ Scribed by Paul Müller; Christian Gränicher
No coin nor oath required. For personal study only.
The course of the thermocatalytic rearrangement of cycloprop‐2‐ene‐1‐carboxylates in the presence of dirhodium(II) tetrakis(perfluorobutyrate) ([Rh~2~(pfb)~4~]) was investigated by varying the substituents of the cyclopropene ring. Product composition is markedly influenced by the number, nature, and position of the substituents, which determine the regio‐ and stereoselectivity of the cyclopropene‐ring cleavage. A mechanism is proposed in which attack of the electrophilic Rh^II^ species is concerted with disrotatory ring opening of the incipient cyclopropyl cation and affords a metal‐complexed vinylcarbene. The chemoselectivity of the latter is consistent with that of other carbenes generated in the presence of [Rh~2~(pfb)~4~].
📜 SIMILAR VOLUMES
Rhodium(k) acetate and rhodium(h) acetamide catalyzed decomposition of diazo esters forms "I-lactones in high yield and with exceptionally high regio-and diastereoselectivity.
Tandem intramolecular generation and rearrangement of allylic oxonium ylides from a-diazo b-keto esters has been effected with the aid of dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate] in toluene, providing benzofuran-3-ones via [2,3]-sigmatropic rearrangement in up to 76% ee. In systems wit