Chiral diphosphine compound intermediate for preparing the same
申请人:Takasago International Corporation
公开号:US05872273A1
公开(公告)日:1999-02-16
A novel diphosphine compound of the formula (I): ##STR1## where R.sup.1 and R.sup.2 represent independently cycloalkyl, unsubstituted or substituted phenyl, or a five-membered heteroaromatic ring. The compound is useful as a ligand for an asymmetric reaction, in particular, as an asymmetric hydrogenation catalyst.
3,3′-Bithiophene-Based Chiral Bisphosphine Oxides as Organocatalysts in Silicon-Derived Lewis Acid Mediated Reactions
作者:Sergio Rossi、Tiziana Benincori、Laura Maria Raimondi、Maurizio Benaglia
DOI:10.1055/s-0039-1690777
日期:2020.4
This account summarizes the development of new biheteroaromatic chiral bisphosphine oxides. 3,3′-Bithiophene-based phosphine oxides (BITIOPOs) have been successfully used as organocatalysts to promote Lewis base catalyzed, Lewis acid mediated stereoselective transformations. These highly electron-rich compounds, in combination with trichorosilyl derivatives (allyltrichlorosilane and silicon tetrachloride)
Allenes in Asymmetric Catalysis: Asymmetric Ring Opening of <i>meso</i>-Epoxides Catalyzed by Allene-Containing Phosphine Oxides
作者:Xiaotao Pu、Xiangbing Qi、Joseph M. Ready
DOI:10.1021/ja9041127
日期:2009.8.5
Unsymmetrically substituted allenes (1,2-dienes) are inherently chiral and can be prepared in optically pure form. Nonetheless, to date the allene framework has not been incorporated into ligands for asymmetric catalysis. Since allenes project functionality differently than either tetrahedral carbon or chiral biaryls, they may create complementary chiral environments. This study demonstrates that optically
Stereospecific Deoxygenation of Phosphine Oxides with Retention of Configuration Using Triphenylphosphine or Triethyl Phosphite as an Oxygen Acceptor
作者:Hai-Chen Wu、Jin-Quan Yu、Jonathan B. Spencer
DOI:10.1021/ol048227c
日期:2004.12.1
[reaction: see text] A new protocol for deoxygenation of various phosphine oxides with retention of configuration is described. The advantage of the new method includes milder conditions and considerably shortened reaction times. Mechanistic studies about the oxygen transfer between the starting phosphine oxide and the sacrificial triphenylphosphine are also presented.
We present a series of low-molecular-weight materials based on cyclic phosphazenes for the use as hostmaterials in bluephosphorescentorganiclight-emittingdiodes. Substituted phenyl rings are attached to the central phosphazene ring either via phosphorus–oxygen bonds to yield phenoxy-substituted derivatives or via direct phosphorus–carbon bonds to yield phenyl-substituted derivatives. The phenoxy
我们提出了一系列基于环状磷腈的低分子量材料,用作蓝色磷光有机发光二极管的主体材料。取代的苯环通过磷-氧键连接至中央磷腈环,以生成苯氧基取代的衍生物,或通过直接的磷-碳键连接以生成苯基取代的衍生物。苯氧基取代的环磷腈是通过苯氧基将六氯环三磷腈中的六个氯原子进行亲核取代而制备的,而苯基取代的环磷腈是在三当量取代的次膦酰胺的环缩合反应中形成的。与苯氧基取代相比,苯基取代导致材料具有更好的热性能。由于与磷腈核的非共轭键合,主体材料的三重态能量非常高,超过3 eV。在使用一种化合物作为主体的饱和蓝色磷光发射体Ir(dbfmi)的OLED器件中,峰值功率效率为7.6 lm W达到–1和5000 cd m –2的峰值亮度。