TY - JOUR
T1 - Synthesis of 2-lithio-1,3-diselenanes and 2-lithio-1,3-dithianes by Se/Li exchange
T2 - First successful trapping of axially oriented 2-lithio-1,3-diselenanes
AU - Krief, A.
AU - Defrère, L.
PY - 1996/10/28
Y1 - 1996/10/28
N2 - Conformationally rigid 2-methylseleno-1,3-diselenanes bearing the methylseleno moiety in axial position react with butyllithiums at low temperature (-130°C) to produce 2-lithio-1,3-diselenanes bearing the lithium in axial position. These organometallics are configurationally stable at -130°C and slowly epimerise at -78°C. Deuteration occurs exclusively from the axial side if carried out at -130°C. 2-Methylseleno-1,3-dithianes behave differently since epimerisation of 2-lithio-1,3-dithianes almost immediately takes place already at -130°C.
AB - Conformationally rigid 2-methylseleno-1,3-diselenanes bearing the methylseleno moiety in axial position react with butyllithiums at low temperature (-130°C) to produce 2-lithio-1,3-diselenanes bearing the lithium in axial position. These organometallics are configurationally stable at -130°C and slowly epimerise at -78°C. Deuteration occurs exclusively from the axial side if carried out at -130°C. 2-Methylseleno-1,3-dithianes behave differently since epimerisation of 2-lithio-1,3-dithianes almost immediately takes place already at -130°C.
UR - http://www.scopus.com/inward/record.url?scp=0030605118&partnerID=8YFLogxK
U2 - 10.1016/0040-4039(96)01813-8
DO - 10.1016/0040-4039(96)01813-8
M3 - Article
AN - SCOPUS:0030605118
SN - 0040-4039
VL - 37
SP - 8015
EP - 8018
JO - Tetrahedron Letters
JF - Tetrahedron Letters
IS - 44
ER -