Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• the Pd(II) intermediate, with retention of the configuration. When 1d-3,3-d2 was used in the presence of the Pd(II) catalyst, only the isotopomer 2d-6-d1 was obtained, indicating the migration of the Pd(II) alkyl complex from the site of the cyclization C(4) to the α-carbonyl position and pointing to

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

Cobalt bis(acetylacetonate)–tert-butyl hydroperoxide–triethylsilane: a general reagent combination for the Markovnikov-selective hydrofunctionalization of alkenes by hydrogen atom transfer

• Xiaoshen Ma and
• Seth B. Herzon

Beilstein J. Org. Chem. 2018, 14, 2259–2265, doi:10.3762/bjoc.14.201

• corresponding metal alkyl complex. This radical then undergoes addition to a second reagent (SOMOphile) to form the functionalized product (Scheme 1). A wide range of manganese, cobalt, or iron-based complexes containing diverse supporting ligands have found use in these reactions. To the best of our knowledge

Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

• Dirk Meyer and
• Thomas Strassner

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

• complexes were fully characterized by standard methods and in three cases also by a solid state structure. Keywords: alkane activation; alkyl complex; NHC; palladium; solid state structure; Introduction Palladium complexes have been shown to be versatile homogeneous catalysts in a variety of reactions [1

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• a phosphido–metal complex that undergoes insertion of the olefin. Protonolysis of the metal–alkyl complex via σ-bond metathesis with the phosphine reagent completes the catalytic cycle giving the product and regenerating the phosphido intermediate. The group of Togni has developed an enantioenriched

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• domino processes. Review Intermolecular reactions involving alkenes Alkenylation reactions of indoles run through a key C–H activation step involving an electrophilic palladation and an electron-deficient Pd(II) catalyst. The mechanism of these reactions involves the generation of a σ-alkyl complex I

• to regenerate a Pd(II) species as active catalyst. Although seldom unambiguously determined, two alternative pathways, based either on “alkene activation” or “indole activation”, have been proposed to explain the formation of the σ-alkyl complex I. The former involves the coordination of the Pd(II

• olefin, may be hypothesized as a plausible way to form the σ-alkyl complex I. In both pathways, indole may be involved directly at the C-2 or C-3 positions as well as preferentially at the C-3 position, in the latter case affording the final 2-substituted product by the intrinsic tendency toward C-3/C-2