Intracellular delivery of a catalytic organometallic complex.

A homogeneous carbene-based palladium catalyst was conjugated to a cell-penetrating peptide, allowing intracellular delivery of catalytically active Pd complexes that demonstrated bioorthogonal activation of a profluorophore within prostate cancer cells.

In-Cell Dual Drug Synthesis by Cancer-Targeting Palladium Catalysts.

Transition metals have been successfully applied to catalyze non-natural chemical transformations within living cells, with the highly efficient labeling of subcellular components and the activation of prodrugs. In vivo applications, however, have been scarce, with a need for the specific cellular targeting of the active transition metals. Here, we show the design and application of cancer-targeting palladium catalysts, with their specific uptake in brain cancer (glioblastoma) cells, while maintaining their catalytic activity. In these cells, for the first time, two different anticancer agents were synthesized simultaneously intracellularly, by two totally different mechanisms (in situ synthesis and decaging), enhancing the therapeutic effect of the drugs. Tumor specificity of the catalysts together with their ability to perform simultaneous multiple bioorthogonal transformations will empower the application of in vivo transition metals for drug activation strategies.

Palladium-mediated in situ synthesis of an anticancer agent.

As a novel prodrug activation strategy Pd(0) nanoparticles, entrapped within a modular polymeric support, were used in cell culture, to synthesise the anticancer agent PP-121 from two non-toxic precursors, thereby inducing cell death in the first example of in situ mediated drug synthesis.

Palladium-mediated chemistry in living cells.

Bioorthogonal metal catalysed chemistry is the application of biocompatible transition metals to catalyse conventional synthetic organic chemistry reactions within a biological environment. Over the past decade, metals which were previously restricted to conventional organic synthesis have begun to be used in an increasing number of biological settings. This has been dominated by copper mediated catalysis of the azide-alkyne Huisgen cycloaddition (1,3-dipolar addition) chemistry but other, less toxic, metals such as palladium are now beginning to establish themselves in the chemical biology/chemical medicine arenas. The potential of palladium mediated chemistry in living systems now ranges from protein modifications to in cellulo synthesis or activation of drugs and suggests that palladium chemistry has the potential to become a powerful tool. In this review we highlight recent advances in Pd-mediated reactions in living systems.

Organocatalytic trifluoromethylation of imines using phase-transfer catalysis with phenoxides. A general platform for catalytic additions of organosilanes to imines.

A new approach to additions of silicon nucleophiles to imines was developed. The method is based on the phase-transfer of phenoxides by ammonium catalysts, overcoming the inability of amide adducts in promoting the reactions.