title: A Convenient Synthesis of 1,2,4- and 1,3,4-Azadiphospholes.
abstract: A new synthetic route to functionalized neutral and anionic azadiphospholes from easily accessible starting materials is described. Equimolar reaction of Na(OCP) and N-(2,6-dimethylphenyl)pivalimidoyl chloride 2 a cleanly affords the imidoxy-functionalized 1,2,4-azadiphosphole 3 a. Using Na(OCP) and imidoyl chloride in a 2:1 ratio leads to an anionic four-membered ring Na[4 a], which has been structurally characterized. During 16 h at room temperature, Na[4 a] rearranges to the anionic 1,3,4-azadiphospholide Na[5 a] with release of carbon monoxide. Applying the more sterically demanding N-(2,6-diisopropylphenyl)pivalimidoyl chloride allows isolation of the 1,3,4-azadiphospholide Na[5 b] in good yield (>70 %). Possible mechanisms leading to the new isomeric azadiphospholides have been investigated with the aid of high-level composite calculations.
authors: Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland.
authors: Riccardo
authors: http://orcid.org/0000-0002-0114-7536
authors: R
authors: Suter
authors: Budapest University of Technology and Economics, Szent Gellért tér 4, 1111, Budapest, Hungary. zbenko@mail.bme.hu.
authors: Zoltán
authors: http://orcid.org/0000-0001-6647-8320
authors: Z
authors: Benkő
authors: Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland. hgruetzmacher@ethz.ch.|Lehn Institute of Functional Materials (LIFM), Sun Yat-Sen University, 510275, Guangzhou, P.R. China. hgruetzmacher@ethz.ch.
authors: Hansjörg
authors: http://orcid.org/0000-0002-1531-8906
authors: H
authors: Grützmacher
keywords: azadiphosphole; cycloaddition; heterocycles; phosphaethynolate; reaction mechanisms