TY - JOUR
T1 - Stoichiometric regio-and stereoselective oxidative coupling reactions of conjugated dienes with ruthenium(0). A mechanistic insight into the origin of selectivity
AU - Hirano, Masafumi
AU - Sakate, Yumiko
AU - Komine, Nobuyuki
AU - Komiya, Sanshiro
AU - Wang, Xian Qi
AU - Bennett, Martin A.
PY - 2011/2/28
Y1 - 2011/2/28
N2 - Treatment of [Ru(η6-C10H8) (η4-1,5-COD)] (1) with excess butadiene at room temperature produces supine,prone-[Ru(η3:η3-2,6-octadiene-1,8- diyl)( η4-1,5-COD)] (supine,prone-2). Similar treatment of 1 with isoprene and (E)-and (Z)-1,3-pentadiene also gives the corresponding analogues of supine,prone-2, while 2,3-dimethylbutadiene does not react. A low-temperature NMR study of the reaction of 1 with butadiene shows initial formation of [Ru(η4-cisoid-butadiene)( η2-transoid-butadiene)( η4-1,5-COD)] (5) as an intermediate, which is spontaneously converted into supine,prone-2 upon warming to room temperature. Similarly, treatment of 1 with (E)-1,3-pentadiene gives two intermediates, [Ru{η4-(E)-cisoid-1,3-pentadiene}{η2-(E) -transoid-1,3-pentadiene}(η4-1,5-COD)] (E-6) and [Ru{η4-(Z)-cisoid-1,3-pentadiene}{η2-(E) -transoid-1,3-pentadiene}(η4-1,5-COD)] (Z-6), in 44/56 ratio at-50 °C. These intermediates are converted into anti-supine,syn-prone- [Ru(η3:η3-3,7-decadiene-2,9-diyl)( η4-1,5-COD)] (anti-supine,syn-prone-4). The observed stereochemistries can be explained by a mechanism that involves oxidative coupling between η 4-(Z)-cisoid-1,3-pentadiene and η2-(E)-transoid-1,3-pentadiene in Z-6.
AB - Treatment of [Ru(η6-C10H8) (η4-1,5-COD)] (1) with excess butadiene at room temperature produces supine,prone-[Ru(η3:η3-2,6-octadiene-1,8- diyl)( η4-1,5-COD)] (supine,prone-2). Similar treatment of 1 with isoprene and (E)-and (Z)-1,3-pentadiene also gives the corresponding analogues of supine,prone-2, while 2,3-dimethylbutadiene does not react. A low-temperature NMR study of the reaction of 1 with butadiene shows initial formation of [Ru(η4-cisoid-butadiene)( η2-transoid-butadiene)( η4-1,5-COD)] (5) as an intermediate, which is spontaneously converted into supine,prone-2 upon warming to room temperature. Similarly, treatment of 1 with (E)-1,3-pentadiene gives two intermediates, [Ru{η4-(E)-cisoid-1,3-pentadiene}{η2-(E) -transoid-1,3-pentadiene}(η4-1,5-COD)] (E-6) and [Ru{η4-(Z)-cisoid-1,3-pentadiene}{η2-(E) -transoid-1,3-pentadiene}(η4-1,5-COD)] (Z-6), in 44/56 ratio at-50 °C. These intermediates are converted into anti-supine,syn-prone- [Ru(η3:η3-3,7-decadiene-2,9-diyl)( η4-1,5-COD)] (anti-supine,syn-prone-4). The observed stereochemistries can be explained by a mechanism that involves oxidative coupling between η 4-(Z)-cisoid-1,3-pentadiene and η2-(E)-transoid-1,3-pentadiene in Z-6.
UR - http://www.scopus.com/inward/record.url?scp=79951860088&partnerID=8YFLogxK
U2 - 10.1021/om100956f
DO - 10.1021/om100956f
M3 - Article
SN - 0276-7333
VL - 30
SP - 768
EP - 777
JO - Organometallics
JF - Organometallics
IS - 4
ER -