Erschienen in:
European Journal of Inorganic Chemistry, 2021 (2021) 38, Seite 4030-4041
Sprache:
Englisch
DOI:
10.1002/ejic.202100648
ISSN:
1434-1948;
1099-0682
Entstehung:
Anmerkungen:
Beschreibung:
AbstractThe C=C bond in selectedN‐alkyl/aryl‐maleimides RN(C(O)CH)2(R=Me,tBu, Ph) is activated by organopnictogen(I) compounds producing bridged bicyclic [2.2.1] products exhibiting bothendoandexoorientations. This is achieved by a synergic element‐ligand cooperation, thereby resembling a hetero‐Diels‐Alder reaction. A wide range of pnictogen(I) complexes is considered in this study including the bis(aldiminine) pincer compounds ArE (1) (Ar=2,6‐(R'N=CH)2C6H3, R’=tBu, E=P (P‐1), As (As‐1), Sb (Sb‐1), Bi (Bi‐1) or R’=Dmp, E=P (P‐1’), As (As‐1’), Sb (Sb‐1’), where Dmp=2,6‐Me2C6H3) and theC,N‐coordinated compounds Ar'E (2) (Ar’=2‐(DippN=CH)C6H4, E=P (P‐2), As (As‐2), where Dipp=2,6‐iPr2C6H3). On this set of compounds, the reversibility of C=C bond activation was examined mainly by means of the1H variable temperature (VT) NMR spectroscopy and this study revealed trends showing a dependence both on the E atom and on the structure of the ligand. The structure of the addition products was elucidated by multinuclear NMR and single‐crystal X‐ray diffraction analysis. The whole study is accompanied by a theoretical survey targeting decisive factors for the C=C bond activation and a preference forendo/exoforms by the particular pnictogen(I) compound.