The not so elusive carbenoid fluoroiodomethyllithium disclosed its electrophilic nature in an unprecedented direct and stereoselective fluorocyclopropanation of allylic alcohols.

Palladium allyl, cinnamyl, and indenyl complexes with the ylide‐substituted phosphines Cy3P+−C−(R)PCy2 (with R=Me (L1) or Ph (L2)) and Cy3P+−C−(Me)PtBu2 (L3) were prepared and applied as defined precatalysts in C−N coupling reactions. The complexes are highly active in the amination of 4‐chlorotoluene with a series of different amines. Higher yields were observed with the precatalysts in comparison to the in situ generated catalysts. Changes in the ligand structures allowed for improved selectivities by shutting down β‐hydride elimination or diarylation reactions. Particularly, the complexes based on L2 (joYPhos) revealed to be universal precatalysts for various amines and aryl halides. Full conversions to the desired products are reached mostly within 1 h reaction time at room temperature, thus making L2 to one of the most efficient ligands in C−N coupling reactions. The applicability of the catalysts was demonstrated for aryl chlorides, bromides and iodides together with primary and secondary aryl and alkyl amines, including gram‐scale applications also with low catalyst loadings of down to 0.05 mol %. Kinetic studies further demonstrated the outstanding activity of the precatalysts with TOF over 10.000 h−1.

Organolithium compounds are amongst the most important organometallic reagents and frequently used in difficult metallation reactions.H owever,t heir direct use in the formation of C À Cbonds is less established. Although remarkable advances in the coupling of aryllithium compounds have been achieved, Csp 2 ÀCsp 3 coupling reactions are very limited. Herein, we report the first general protocol for the coupling or aryl chlorides with alkyllithium reagents.P alladium catalysts based on ylide-substituted phosphines (YPhos) were found to be excellently suited for this transformation giving high selectivities at room temperature with avariety of aryl chlorides without the need for an additional transmetallation reagent. This is demonstrated in gram-scale synthesis including building blocks for materials chemistry and pharmaceutical industry.Furthermore,the direct coupling of aryllithiums as well as Grignard reagents with aryl chlorides was also easily accomplished at room temperature.

Organolithium compounds are amongst the most important organometallic reagents and frequently used in difficult metallation reactions.H owever,t heir direct use in the formation of C À Cbonds is less established. Although remarkable advances in the coupling of aryllithium compounds have been achieved, Csp 2 ÀCsp 3 coupling reactions are very limited. Herein, we report the first general protocol for the coupling or aryl chlorides with alkyllithium reagents.P alladium catalysts based on ylide-substituted phosphines (YPhos) were found to be excellently suited for this transformation giving high selectivities at room temperature with avariety of aryl chlorides without the need for an additional transmetallation reagent. This is demonstrated in gram-scale synthesis including building blocks for materials chemistry and pharmaceutical industry.Furthermore,the direct coupling of aryllithiums as well as Grignard reagents with aryl chlorides was also easily accomplished at room temperature.

s-Block metal carbenoids are carbene synthons and applied in a myriad of organic transformations. They exhibit a strong structure-activity relationship, but this is only poorly understood due to the challenging high reactivity and sensitivity of these reagents. Here, we report on systematic VT and DOSY NMR studies, XRD analyses as well as DFT calculations on a sulfoximinoyl-substituted model system to explain the pronounced solvent dependency of the carbenoid stability. While the sodium and potassium chloride carbenoids showed high stabilities independent of the solvent, the lithium carbenoid was stable at room temperature in THF but decomposed at À10 8C in toluene. These divergent stabilities could be explained by the different structures formed in solution. In contrast to simple organolithium reagents, the monomeric THF-solvate was found to be more stable than the dimer in toluene, since the latter more readily forms direct Li/Cl interactions which facilitate decomposition via a-elimination.