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Synthese von 1,2,5‐Azastannaborol‐Derivaten aus Schwefeldiimid‐Anionen und cis ‐Stannyl‐boryl‐alkenen – Röntgenstrukturanalyse von zwei 2,5‐Dihydro‐1‐(imino‐λ 4 ‐sulfanyliden)‐1,2,5‐azastannaboratolen
Author(s) -
Wrackmeyer Bernd,
Frank Stefan M.,
Herberhold Max,
Borrmann Horst,
Simon Arndt
Publication year - 1991
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19911240404
Subject(s) - chemistry , medicinal chemistry , stereochemistry
Synthesis of 1,2,5‐Azastannaborole Derivatives from Sulfur Diimide Anions and cis ‐Stannyl‐boryl‐alkenes – X‐ray Crystallographic Study of Two 2,5‐Dihydro‐1‐(imino‐λ 4 ‐sulfanylidene)‐1,2,5‐azastannaboratoles ( E )‐3‐(Diethylboryl)‐2‐(chlorodimethylstannyl)‐2‐pentene (1) reacts with the sulfur diimide anions 3 [R – NSN − K + , R= t Bu ( a ), Me 3 Si ( b ), t Bu 2 P ( c )] in a 1:1 ratio, and with 4 (K +;− NSN − K + ) in a 2:1 ratio, to give various heterocycles. The first products of the reaction between 1 and 3 [2,5‐dihydro‐1‐(imino‐λ 4 ‐sulfanylidene)‐1,2,5‐azastannaboratoles 5a, b, c ] are isolated at −30°C and characterized by X‐ray crystallography. The compounds 5a,b rearrange into the borole derivates 6a,b (with an additional NSn coordination) by transfer of an ethyl group from the boron to the sulfur atom. Ethylene is eliminated from compound 6a (not 6b ) to give the diaminosulfane derivative 7a . The 2:1 reaction between 1 and 4 affords an unstable intermediate 8 with a fluxional structure, leading to 9 in which an EtS moiety bridges a borole ring (analogous to 6 but without the additional N – Sn coordination) and a boratole ring (analogous to 5 ). All compounds are characterized by 1 H‐, 11 B‐, 13 C‐, 15 N‐ (in part), 29 Si‐ and 119 Sn‐NMR spectra.