ISSN:
0009-2940
Keywords:
Silicon compounds
;
Ylides
;
NMR, 13C, 17O, 29Si
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Two series of aminophosphonium ylides with reactive alkoxychlorosilyl substituents (R2N)3P=CHSi(OR')2Cl (1-8, R = Me, Et/R' = Me, Et, iPr, tBu) have been prepared by reaction of the aminophosphonium ylides (R2N)3P = CH2 with the corresponding dialkoxydichlorosilanes Cl2Si(OR')2. Substituent effects have been investigated by heteronuclear solution NMR studies of the nuclei 1H, 13C, 15N, 17O, 29Si, and 31P. These studies show an alternating shielding effect along the C-O-Si-C backbone. Further reactions of the chlorosilylated ylides with the aminomethylenephosphorane (Me2N)3P=CH2 lead to the formation of the bis-ylidic compounds [(Me2N)3P=CH]2Si(OR')2 (9, 10), which are also available in one-pot syntheses. The molecular structure of [(Me2N)3P=CH]2Si(OiPr)2 (9) has been confirmed by single-crystal X-ray diffraction. In the crystal the molecules have two ylidic carbon centers with planar configuration, which are bridged by a nearly tetrahedral silicon atom. Short P-C and Si-C distances indicate a stabilizing effect of the carbanionic centers.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19941270908
Permalink
