Transition‐Metal‐Free Intermolecular Hydrocarbonation of Styrenes Mediated by NaH/1,10‐Phenanthroline
摘要:
AbstractA transition‐metal‐free intermolecular coupling reaction of halocompounds with styrenes in the presence of NaH and 1,10‐phenanthroline was developed. This reaction afforded hydrocarbonated products with complete anti‐Markovnikov selectivity. The method allows the use of a wide range of halocompounds, including aryl and alkyl halides, and good functional group tolerance. Detailed mechanistic studies indicated that an anilide anion generated in situ by the NaH‐mediated reduction of 1,10‐phenanthroline works as an electron donor and a hydrogen source.
Palladium-Catalyzed Oxidative Intermolecular Difunctionalization of Terminal Alkenes with Organostannanes and Molecular Oxygen
作者:Kaveri Balan Urkalan、Matthew S. Sigman
DOI:10.1002/anie.200900218
日期:2009.4.14
palladium complex catalyzes the title transformations, which are thought to proceed via a π‐allyl or π‐benzyl intermediate. The regioselectivity of the reaction (1,2‐ or 1,1‐difunctionalization) depends on the type of terminal double bond (conjugated or nonconjugated) in the substrate (see scheme) and appears to be controlled by the relative rates of β‐hydride elimination and transmetalation. DMA=dimethylacetamide
Catalytic amounts of 1,3-di(methyl)imidazole-2-ylidene, one of the simplest and most prototypical N-heterocyclic carbenes, can up-convert aldehydes into powerful stoichiometric sources of electrons (Super Electron Donors) for reductive transformations of iodoaryls (Ered < −2 V). In particular, the hydroarylation of 1,1′-diarylethylenes, which may require high temperatures and inherently generate stoichiometric