84010-91-3Relevant academic research and scientific papers
Polar substituent effects on NMR chemical shifts of group 14 elements: Synthesis and NMR (13C, 29Si, 119Sn, and 207Pb) substituent chemical shifts (SCS) of 4-substituted bicyclo[2.2.2]oct-1-ylbutanes, -trimethylsilanes, -trimethylstannanes, and -trimethylplumbanes (M(CH3)3, M = C, Si, Sn, and Pb) and ...
Adcock, William,Gangodawila, Hemakanthi,Kok, Gaik B.,Iyer, V. Sankar,Kitching, William,Drew, Gregory M.,Young, David
, p. 156 - 166 (2008/10/08)
Full title: Polar substituent effects on NMR chemical shifts of group 14 elements: Synthesis and NMR (13C, 29Si, 119Sn, and 207Pb) substituent chemical shifts (SCS) of 4-substituted bicyclo[2.2.2]oct-1-ylbutanes, -trimethylsilanes, -trimethylstannanes, and -trimethylplumbanes (M(CH3)3, M = C, Si, Sn, and Pb) and 4-substituted bicyclo[2.2.1]hept-1-yltrimethylstannanes. An extensive series of 4-substituted bicyclo[2.2.2]oct-1-yltrimethylstannanes (2a) and 4-substituted bicyclo[2.2.1]hept-1-yltrimethylstannanes (3a) has been synthesized and characterized and the 119Sn chemical shifts measured. A remarkably wide range of substituent chemical shifts (SCS; ca. 20 ppm) are obtained for system 2a, and these have been analyzed in terms of possible substituent-probe interactions. Comparisons have been made between systems 2a and 3a, but the signs of the 119Sn substituent chemical shifts (SCS) for the two systems are diametrically opposed, indicating a different blend of through-space and through-bond effects. Some 4-substituted 1-tert-butylbicyclo[2.2.2]octanes (2b) as well as more restricted series of trimethylsilanes and trimethylplumbanes (2c and 2d, respectively) have also been acquired and their 13C, 29Si, and 207Pb SCS measured and compared with those of the stannane series. Synthetic approaches that provide efficient access to some 1,4-disubstituted bicyclo[2.2.2]octyl systems are outlined.
