Enantioselective 1,3-Dipolar Cycloaddition of Nitrones to Methacrolein Catalyzed by (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)M{(<i>R</i>)-Prophos} Containing Complexes (M = Rh, Ir; (<i>R</i>)-Prophos = 1,2-bis(Diphenylphosphino)propane): On the Origin of the Enantioselectivity
作者:Daniel Carmona、M. Pilar Lamata、Fernando Viguri、Ricardo Rodríguez、Luis A. Oro、Fernando J. Lahoz、Ana I. Balana、Tomás Tejero、Pedro Merino
DOI:10.1021/ja0539443
日期:2005.9.28
[(eta(5)-C(5)Me(5))M(R)-Prophos}(H(2)O)](2+) ((R)-Prophos = 1,2-bis(diphenylphosphino)propane) efficiently catalyze the enantioselective 1,3-dipolar cycloaddition of nitrones to methacrolein. Reactions occur with perfect endo selectivity and with enantiomeric excesses up to 96%. Intermediates [(eta(5)-C(5)Me(5))M(R)-Prophos}(methacrolein)](SbF(6))(2) (M = Rh (3), Ir (4)) have been spectroscopically and
铑和铱路易斯酸阳离子 [(eta(5)-C(5)Me(5))M(R)-Prophos}(H(2)O)](2+) ((R)-Prophos = 1,2-双(二苯基膦基)丙烷)有效地催化硝酮对异丁烯醛的对映选择性 1,3-偶极环加成反应。反应以完美的内向选择性和高达 96% 的对映体过量发生。中间体 [(eta(5)-C(5)Me(5))M(R)-Prophos}(methacrolein)](SbF(6))(2) (M = Rh (3), Ir (4) ) 已被光谱学和晶体学表征。硝酮复合物 [(eta(5)-C(5)Me(5))M(R)-Prophos}(nitrone)](SbF(6))(2) (M = Rh, nitone = 1-pyrrolidine N-氧化物 (5), 2,3,4,5,-四氢吡啶 N-氧化物 (6), 3,4-二氢异喹啉 N-氧化物 (7); M = Ir