Diastereospecific Control in the Synthesis of Enantiomerically Pure Bis-Equatorial Rhodium(II) Catalysts by Chiral Phosphanes
作者:Pascual Lahuerta、Eduardo Moreno、Angeles Monge、Guillermo Muller、Julia Pérez-Prieto、Mercedes Sanaú、Salah-Eddine Stiriba
DOI:10.1002/1099-0682(200012)2000:12<2481::aid-ejic2481>3.0.co;2-m
日期:2000.12
R = CF3] and (M)-Rh2(μ-O2CR)2(η1-O2CR)2η2-(−)-PPh2(CH−R*−OH)}2 [M(−)1, R = CH3; M(−)2, R = CF3] in a high yield. Their synthesis, characterisation and catalytic behaviour in metal−carbenoid reactions are reported. X-ray analysis of P(+)2 and M(−)2 shows, in each case, a Rh24+ unit supported by two bridging and two monodentate trifluoroacetates; two phosphanes, (+)PPh2(CH−R*−OH) or (−)PPh2(CH−R*−OH)
Rh2(O2CR)4 [R = CH3, CF3] 与手性膦 (1S,2S,5R)-(2-羟基-5-异丙烯基-2-甲基环己基)(二苯基)膦的反应,(+)PPh2( CH-R*-OH) 或其对映异构体 (1R,2R,5S)-(2-羟基-5-异丙烯基-2-甲基环己基)(二苯基)膦,(-)-PPh2(CH-R*-OH),导致产物 (P)-Rh2(μ-O2CR)2(η1-O2CR)2η2-(+)PPh2(CH−R*−OH)}2 [P(+)1, R = CH3; P(+)2 R = CF3] 和 (M)-Rh2(μ-O2CR)2(η1-O2CR)2η2-(-)-PPh2(CH-R*-OH)}2 [M(-) 1、R=CH3;M(-)2, R = CF3] 高产率。报道了它们在金属-类胡萝卜素反应中的合成、表征和催化行为。P(+)2 和 M(-)2 的 X 射线分析显示,在每种情况下,Rh24+ 单