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Updated: Jun 23, 2026

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Synthesis, microwave spectrum, and conformational equilibrium of propa-1,2-dienethiol (H(2)=C=CHSH)
Harald Møllendal1, Brahim Khater, Jean-Claude Guillemin
1Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, NO-0315 Oslo, Norway. harald.mollendal@kjemi.uio.no
Abstract:
The first synthesis of the kinetically unstable compound propa-1,2-dienethiol (allenethiol; H(2)CCCHSH) is reported. Its microwave spectrum has been studied in the 41.5-80 GHz spectral range. The spectra of two rotameric forms have been assigned. The C-C-S-H chain of atoms is synperiplanar (0 degrees ) in one of the conformers. This dihedral angle is anticlinal in the second rotamer forming an angle of 140(5) degrees in the second form. The synperiplanar conformer is found to be 1.0(6) kJ/mol more stable than the anticlinal rotamer. The microwave study has been augmented by quantum chemical calculations at the MP2/aug-cc-pVTZ and B3LYP/6-311++G** levels of theory. The predictions of these two theoretical methods are in excellent agreement with the experimental findings.
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