Rationally designed fluorene-based mono- and bimetallic Pd-PEPPSI complexes were synthesized and demonstrated to be effective for the one-pot sequential α-arylation/alkylation of oxindoles. This streamlined approach offers efficient access to functionalized 3,3-disubstituted oxindoles in excellent yields (up to 89%) under mild reaction conditions.

Rh(I) NHC and Rh(III) Cp* NHC complexes (Cp* = pentamethylcyclopentadienyl, NHC=N-heterocyclic carbene = pyrid-2-ylimidazol-2-ylidene (PyÀ Im), thiophen-2-ylimidazol-2ylidene) are presented. Selected catalysts were selectively immobilized inside the mesopores of SBA-15 with average pore diameters of 5.0 and 6.2 nm. Together with their homogenous progenitors, the immobilized catalysts were used in the hydrosilylation of terminal alkynes. For aromatic alkynes, both the neutral and cationic Rh(I) complexes showed excellent reactivity with exclusive formation of the β(E)-isomer. For aliphatic alkynes, however, selectivity of the Rh(I) complexes was low. By contrast, the neutral and cationic Rh(III) Cp* NHC complexes proved to be highly regio-and stereoselective catalysts, allowing for the formation of the thermodynamically less stable β-(Z)-vinylsilane isomers at room temperature. Notably, the SBA-15 immobilized Rh(I) catalysts, in which the pore walls provide an additional confinement, showed excellent β-(Z)-selectivity in the hydrosilylation of aliphatic alkynes, too. Also, in the case of 4aminophenylacetylene, selective formation of the β(Z)-isomer was observed with a neutral SBA-15 supported Rh(III) Cp* NHC complex but not with its homogenous counterpart. These are the first examples of high β(Z)-selectivity in the hydrosilylation of alkynes by confinement generated upon immobilization inside mesoporous silica.

Monometallic and bimetallic palladium(II)/N-heterocyclic carbenec omplexes appended with naphthalimide or bisnaphthalimide moieties were designed, synthesized, and characterized. Employment of these catalysts brings about the stepeconomic and regioselective heteroannulationo f tertiary propargyl alcohols with o-haloanilines resulting in biologically and pharmaceutically relevant 2-alkenylindoles.Basis for the regioselective heteroannulation is unraveled by coordination of the propargylic hydroxy moiety to palladium during insertion. Embracing this methodology,asingle regioisomer of unsymmetrical 2,3-disubstitutedi ndoles could be achieved throughl ate-stage modification. Ther ole of the naphthalimide or bisnaphthalimide appended to the NHC on the catalytic efficiency has been studied.

Ketones are the key functional group that recurs in chemistry and biology, and accessing them through simple and economic ways is highly desirable. Herein, we report the synthesis of unsymmetrical ketones from abundant toluene and alkyl esters, where volatile alcohols are the sole byproduct. This protocol applies to a repertoire of substrates bearing electron-donating, electron-withdrawing, and neutral substituents. Most importantly, the organometallic ferrocenyl ester underwent aroylation with ease. This method is the first example to furnish diketones from methyl arenes and diesters. Furthermore, cyclic imide was synthesized by this protocol utilizing KN(SiMe 3 ) 2 as a 'nitrogen' source. Density functional theory studies provide insight into deprotonation of toluene by K + -π interaction by increasing its acidity, and this being the rate-determining step.

A straightforward protocol to acylate oxindoles using methyl and phenyl esters mediated by LiHMDS and KOtBu respectively via the mixed Claisen condensation under mild reaction conditions.