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Updated: Aug 31, 2025

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Concerted addition of aldehydes to the singlet biradical [P(μ-NTer)]2
Jan Rosenboom1, Alexander Villinger1, Axel Schulz1,2
1Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany. jonas.bresien@uni-rostock.de.
Abstract:
The reaction of the singlet biradical [P(μ-NTer)]2 with various aldehydes selectively yielded the corresponding [2.1.1]-bicyclic addition products in a very fast reaction. All products were fully characterized, including by NMR and vibrational spectroscopy as well as single-crystal X-ray diffraction. The mechanism of the addition was investigated theoretically using high-level ab initio methods (CCSD(T) with triple- and quadruple-zeta basis sets) and corresponds to a concerted cycloaddition reaction with a very low activation barrier. For comparison, the mechanisms of the literature-known cycloadditions of H2, alkenes, and alkynes were also studied, indicating a similar reaction profile for all unsaturated reactants.
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