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[3 + 2] Cycloaddition of Diazomethane Derivatives to Perfluoro‐2‐phosphapropene
Author(s) -
Grobe J.,
Armbrecht A.,
Van D. Le,
Krebs B.,
Kuchinke J.,
Läge M.,
Würthwein E.U.
Publication year - 2001
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200106)627:6<1241::aid-zaac1241>3.0.co;2-4
Subject(s) - cycloaddition , diazomethane , chemistry , diazo , derivative (finance) , nuclear magnetic resonance spectroscopy , stereochemistry , medicinal chemistry , organic chemistry , catalysis , financial economics , economics
Perfluoro‐2‐phosphapropene ( 1 ) reacts with diazo compounds R(H)C=N 2 (R = H ( 2 a ), Ph ( 2 b ), CO 2 Et ( 2 c ), Me 3 Si ( 2 d )) at low temperatures regioselectively yielding via 1,3‐H shift the novel 1,2,3‐diazaphospholes 4 a – d . The mesomerically stabilized compounds 4 b and 4 c were characterized by NMR spectroscopy and single crystal X‐ray diffraction studies. Using diphenyldiazomethane 5 as partner for 1 , the cycloaddition is spontaneously followed by N 2 elimination to give the crystalline phosphirane derivative 7 . The analogous reaction of 1 with 9‐diazofluorene 9 unexpectedly leads to the so‐far unknown 1,2‐diphosphinane compound 11 . Quantum chemical calculations for the gas phase on DFT and RHF level prove that for both the perhydro‐ and the perfluoro‐2‐phosphapropene the [3 + 2]‐cycloaddition is kinetically determined and that, due to high stability of the products, the thermodynamic equilibrium with the slightly more stable isomers is not accessible.