作者:William Clegg、Thorsten R. F. Johann、Todd B. Marder、Nicholas C. Norman、A. Guy Orpen、Torren M. Peakman、Michael J. Quayle、Craig R. Rice、Andrew J. Scott
DOI:10.1039/a800108a
日期:——
The chiral diborane(4) compounds B2[R,R-O2CH(CO2Me)CH(CO2Me)]2, B2(S-O2CH2CHPh)2, B2(R,R-O2CHPhCHPh)2 and B2(O2C20H12)2 (O2C20H12 = 1,7′-bi-2-naphtholate) have been synthesized. All four compounds have been characterised by X-ray crystallography, the latter as a racemate. The B–B bond oxidative-addition reactions of the first three compounds with [Pt(PPh3)2(η-C2H4)] resulted in the platinum(II) bis(boryl) complexes cis-[Pt(PPh3)2B[R,R-O2CH(CO2Me)CH(CO2Me)]}2], cis-[Pt(PPh3)2B(S-O2CH2CHPh)}2] and cis-[Pt(PPh3)2B(R,R-O2CHPhCHPh)}2]; the former two were also characterised by X-ray crystallography. The platinum-catalysed diborations of a range of prochiral 1,3-dienes with the compounds B2[R,R-O2CH(CO2Me)CH(CO2Me)]2, B2(S-O2CH2CHPh)2 and B2(R,R-O2CHPhCHPh)2 were studied. Although these reactions were clean and quantitative, observed product d.e.s (measured by 1H NMR spectroscopy) were low or non-existent indicating that chirality transfer from the diborane(4) diolate groups to the diene diboration product is not efficient in these cases.
我们合成了手性二硼烷(4)化合物 B2[R,R-O2CH(CO2Me)CH(CO2Me)]2、B2(S-O2CH2CHPh)2、B2(R,R-O2CHPhCHPh)2 和 B2(O2C20H12)2(O2C20H12 = 1,7′-联-2-萘酚)。这四种化合物均已通过 X 射线晶体学鉴定,其中后者是外消旋体。前三种化合物与[Pt(PPh3)2(η-C2H4)]的 B-B 键氧化加成反应生成了铂(II)双(硼烷基)配合物 cis-[Pt(PPh3)2B[R、R-O2CH(CO2Me)CH(CO2Me)]}2], cis-[Pt(PPh3)2B(S-O2CH2CHPh)}2] and cis-[Pt(PPh3)2B(R,R-O2CHPhCHPh)}2];前两者还通过 X 射线晶体学进行了表征。研究了铂催化的一系列亲手性 1,3 二烯与化合物 B2[R,R-O2CH(CO2Me)CH(CO2Me)]2、B2(S-O2CH2CHPh)2 和 B2(R,R-O2CHPhCHPh)2 的二硼化反应。虽然这些反应是干净的定量反应,但观察到的产物 d.e.s(通过 1H NMR 光谱测量)很低或不存在,这表明在这些情况下,从二硼烷(4)二酸酯基团到二烯烃二重化产物的手性转移并不有效。