A method for regioselective cyanation of heterocycles has been developed. A number of aromatic heterocycles as well as azulene can be cyanated in reasonable to good yields by using a copper cyanide ...catalyst and an iodine oxidant.
Palladium diimine-catalyzed polymerization of olefins using unsaturated alcohols as chain-transfer agents has been demonstrated. The reaction affords aldehyde end-capped polymers whose molecular ...weight can be tuned by varying the ratio of olefin/chain-transfer agent. Notably, >95% efficient end capping with aldehyde can be achieved under optimized conditions. This end-capping procedure is a rare example of introducing a highly reactive and versatile terminal functionality in polyolefin chains using a functional group-tolerant late metal catalyst. The reactivity of these end-capped polymers is illustrated here via functionalization with dyes to yield colored, hydrocarbon-soluble polyolefin derivatives.
A thousand turnovers in bi‐ and triaryl formation: Substituted anilides have been ortho‐arylated by aryl iodides under palladium catalysis (see scheme). This method is highly tolerant of the presence ...of additional functional groups (FGs). Even an iodo functionality on the anilide moiety and a bromo functionality on the aryl iodide are compatible with this methodology.
A method for the palladium-catalyzed arylation of pyridines and pyrazoles has been developed. Both aliphatic and aromatic C−H bonds may be functionalized using this method. A bromo substituent is ...tolerated on the aryl iodide coupling component.
Lithium 1,1-diadamantylamide (LDAM) base-promoted insertion of arynes into disulfide S-S bonds is described. After generation of arynes from readily available aryl halides and triflates, reactions ...with diaryl and diisopropyl disulfides afford the insertion products in moderate to excellent yields. Use of 1-cyclohexenyl triflate gave an excellent yield of 1,2-bis(phenylthio)cyclohexene.
The palladium-catalyzed direct arylation of anilides possessing several N-acyl substituents has been demonstrated. Removal of the acyl group by base hydrolysis allows a short and efficient synthesis ...of 2-aryl or 2,6-diarylanilines. The method is functional group tolerant and allows the presence of chloride and bromide substituents on both the anilide and aryl iodide coupling components. The arylation products can be converted to phenanthridines by the reaction with trifluoroacetic anhydride.
A method for iron-catalyzed deprotonative alkylation of arene C−H bonds by alkyl iodides and bromides has been developed. In the presence of an amide base, both primary and secondary alkyl halides ...can be coupled with furans, thiophenes, pyridine derivatives, and some electron-withdrawing-group containing arenes.
Neutral nickel methyl complexes incorporating 2,8-diarylnaphthyl groups have been synthesized and characterized. Salicylaldiminato nickel systems 1a,b are exceptionally active neutral nickel single ...component catalysts for the polymerization of ethylene capable of producing lightly branched ultrahigh-molecular-weight polyethylene (UHMWPE). In addition, complex 1a shows a “quasi-living” polymerization behavior.
Give a direction: A rationally designed, removable meta‐directing group enables the selective, remote functionalization of aromatic substrates (see scheme). The generality of the concept was shown ...with alkenylation reactions of hydrocinnamic acid derivatives, the selectivities of which were similar to the ones described for benzyl derivatives.
Synthesis and full characterization of cationic isostructural “sandwich” diimine-coinage metal ethylene complexes are reported. Ethylene self-exchange kinetics proceeds by an associative exchange ...mechanism for Cu and Au complexes. The fastest ligand exchange was observed for Ag complex 8a. The upper limit of ΔG ⧧, assuming associative ligand exchange, was found to be ca. 5.0 kcal/mol. Ethylene self-exchange in Cu complex 7b proceeds with ΔG 298 ⧧ = 12.9 ± 0.1 kcal/mol, while the exchange is the slowest in Au complex 9, with ΔG 298 ⧧ = 16.7 ± 0.1 kcal/mol. Copper complex 7b is unusually stable and can survive in air for years.
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