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New Ga/N‐based Active Lewis Pairs, Trifunctional Ga–Ga Compounds, Reactions with Cyanamide and Dual Insertion of Isocyanate
Author(s) -
Uhl Werner,
Hengesbach Frank,
Isermann Jennifer,
Soleimani Meisam,
Schürmann Lina,
Hepp Alexander,
Layh Marcus
Publication year - 2019
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/zaac.201900195
Subject(s) - chemistry , adduct , nitrile , stereochemistry , dimer , lewis acids and bases , isocyanate , medicinal chemistry , yield (engineering) , cyanamide , organic chemistry , catalysis , materials science , metallurgy , polyurethane
Hydrogallation of Me 3 Si–C≡C–NR' 2 with R 2 Ga–H (R = t Bu, CH 2 t Bu, i Bu) yielded Ga/N‐based active Lewis pairs, R 2 Ga–C(SiMe 3 )=C(H)–NR' 2 ( 7 ). The Ga and N atoms adopt cis ‐positions at the C=C bonds and show weak Ga–N interactions. t Bu 2 GaH and Me 3 Si–C≡C–N(C 2 H 4 ) 2 NMe afforded under exposure of daylight the trifunctional digallium(II) compound [MeN(C 2 H 4 ) 2 N](H)C=C(SiMe 3 )Ga( t Bu)–Ga( t Bu)C(SiMe 3 )=C(H)[N(C 2 H 4 ) 2 NMe] ( 8 ), which results from elimination of isobutene and H 2 and Ga–Ga bond formation. 8 was selectively obtained from the ynamine and [ t Bu(H)Ga–Ga(H) t Bu] 2 [HGa t Bu 2 ] 2 . 7a (R = t Bu; NR' 2 = 2,6‐Me 2 NC 5 H 8 ) and H 8 C 4 N–C≡N afforded the adduct t Bu 2 Ga‐C(SiMe 3 )=C(H)(2,6‐Me 2 NC 5 H 8 ) · N≡C–NC 4 H 8 ( 11 ) with the nitrile bound to gallium. The analogous ALP with harder Al atoms yielded an adduct of the nitrile dimer or oligomers of the nitrile at room temperature. The reaction of 7a with Ph–N=C=O led to the insertion of two NCO groups into the Ga–C vinyl bond to yield a GaOCNCN heterocycle with Ga bound to O and N atoms ( 12 ).