ISSN:
0009-2940
Keywords:
Organoboration
;
Tin compounds
;
NMR, multinuclear
;
NMR, 119Sn
;
NMR, solid-state
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The organoboration of tetraalkynyltin compounds [Sn-(C≡CR1)4 (1): R1 = Me (a), Et (b), Pr (c), iPr (d), tBu (e)] with triethylborane (2) proceeds stepwise. Intermediates with a cationic triorganotin (3, 5) and a dicationic diorganotin fragment (4), stabilized by intramolecular coordination of one and two alkynyl moieties, respectively, were isolated (3e, 4a) and/or identified by multinuclear NMR in solution (1H, 11B, 13C, 119Sn) and in the solid state (13C and 119Sn CP/MAS) (3e, 4a). The magnitude of 1J(13C≡13C) in 4a (101.0 Hz) is significantly smaller than that for sodium triethyl-1-propynylborate (7) (119.2 Hz), proving the weak coordination of the C≡C bond to the dicationic tin fragment. The final products of the organoboration, 1,4,6,9-tetraalkyl-2,7-bis(diethylboryl)-3,8-diethyl-5-stannaspiro[4.4]nona-1,3,6,8-tetraenes (6b-6e) were obtained in high yield.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250714
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