No abstract

We describe a visible-light-promoted addition of a hydrogen atom and an acetal carbon toward various electrondeficient alkenes. 1,3-Dioxolane is converted to its radical species in the presence of persulfate and an iridium catalyst upon visible light irradiation, which then reacts with electron-deficient alkenes. The reaction operates via a radical chain mechanism, a less commonly observed pathway for this class of transformation. Hydrogen atom transfer from 1,3-dioxolane to α-malonyl radicals is corroborated by experimental and density functional theory studies.

<p>The Suzuki-Miyaura coupling is one of the most frequently used reactions in organic synthesis. Recent work by others suggested that an arylamine, prepared by palladium catalysis and tricyclohexylphosphine, could catalyze Suzuki-Miyaura coupling reactions without transition metals. Herein, we used a fluorometric quantification method for palladium previously developed in our laboratory to unambiguously conclude that there is a correlation between the palladium content in the arylamine and the rate of a Suzuki-Miyaura coupling. Also, our mass spectroscopic analysis of the arylamine revealed the presence of a palladium-phosphine complex. When Pd(OAc)₂ was used as a catalyst for the same Suzuki-Miyaura coupling, tricyclohexylphosphine was detrimental to the coupling and that the arylamine played negligible role. This study demonstrates the utility of the fluorometric technology for catalysis research.<br></p>

The previous synthetic strategy for the preparation of non‐fluorescent fluoresceins was mostly limited to the double addition of simple alkenes and alkynes. We report the one‐step masking of Pittsburgh Green to its mono‐alkylated or esterified compounds. Unlike previous syntheses, this strategy tolerates a broader range of functional groups as masking groups. We also demonstrate the advantage of mono‐alkylation over di‐alkylation for metal detection.

<p>The Suzuki-Miyaura coupling is one of the most frequently used reactions in organic synthesis. Recent work by others suggested that an arylamine, prepared by palladium catalysis, could catalyze Suzuki-Miyaura coupling reactions without transition metals. Herein, we used a fluorometric quantification method for palladium previously developed in our laboratory to unambiguously conclude that there is a correlation between the palladium content in the arylamine and the rate of a Suzuki-Miyaura coupling. Also, our mass spectroscopic analysis of the arylamine revealed the presence of a palladium-phosphine complex. We discovered that the phosphine was detrimental to the palladium catalysis and that the arylamine played negligible role. This study demonstrates the utility of the fluorometric technology for catalysis research.</p>