TY - JOUR
T1 - Negative hyperconjugation control of acidities in α-trimethylsilyl substituted α-picolines
T2 - isolation of [Li{NC5H4-2-C(H)(SiMe3)2}{NC5H4-2-C(H)(SiMe3)}]2
AU - Jones, Cameron
AU - Kennard, Colin H.L.
AU - Raston, Colin L.
AU - Smith, Graham
PY - 1990/10/16
Y1 - 1990/10/16
N2 - Isolation of [{Li(R′H)(R)}2] (1) (R- = NC5H4-2-CH(SiMe3), R′H = NC5H4-2-RH(SiMe3)2), where R′H acts as an N-donor and R- as an η3-aza-allyl unit to one metal centre and an N-bridge to the other (X-ray structure determination), and formation of [{Li(R)(tmeda)}2] and R′H on treatment of (1) with tmeda (= N,N,N′,N′-tetramethylethylenediamine) establishes the relative solution thermodynamic acidities RH > R′H, rationalized by negative hyperconjugation in RH overriding extra polarization from two silicon centres in R′H.
AB - Isolation of [{Li(R′H)(R)}2] (1) (R- = NC5H4-2-CH(SiMe3), R′H = NC5H4-2-RH(SiMe3)2), where R′H acts as an N-donor and R- as an η3-aza-allyl unit to one metal centre and an N-bridge to the other (X-ray structure determination), and formation of [{Li(R)(tmeda)}2] and R′H on treatment of (1) with tmeda (= N,N,N′,N′-tetramethylethylenediamine) establishes the relative solution thermodynamic acidities RH > R′H, rationalized by negative hyperconjugation in RH overriding extra polarization from two silicon centres in R′H.
UR - http://www.scopus.com/inward/record.url?scp=0002271172&partnerID=8YFLogxK
U2 - 10.1016/0022-328X(90)85482-E
DO - 10.1016/0022-328X(90)85482-E
M3 - Article
AN - SCOPUS:0002271172
SN - 0022-328X
VL - 396
SP - c39-c42
JO - JOURNAL OF ORGANOMETALLIC CHEMISTRY
JF - JOURNAL OF ORGANOMETALLIC CHEMISTRY
IS - 2-3
ER -