由手性膦BINAP容易制备的手性膦氧化物BINAPO在三氯甲硅烷基化合物通过高价硅酸盐中间体的反应中表现出良好的催化活性。在催化量的BINAPO存在下,醛与烯丙基三氯硅烷的烯丙基化反应使烯丙基化的加合物具有良好的对映选择性(最高79%ee),其中二异丙基乙胺和四丁基碘化铵作为添加剂的组合对于加速催化循环至关重要。31氧化膦的1 P NMR分析表明,胺促进了氧化膦从硅原子上的解离。BINAPO还促进了二异丙基乙胺作为添加剂存在下醛与三氯甲硅烷基烯醇醚的对映体选择性醛醇缩合反应,从而以高非对映体和对映体选择性(最高syn / anti = 1 / 25,96%ee(anti))提供了相应的醛醇加合物。)。
Chiral Phosphoramide-Catalyzed Aldol Additions of Ketone Enolates. Preparative Aspects
作者:Scott E. Denmark、Robert A. Stavenger、Ken-Tsung Wong、Xiping Su
DOI:10.1021/ja984123j
日期:1999.6.1
Trichlorosilyl enolates of ketones (enoxytrichlorosilanes) were demonstrated to be highly reactive aldoladdition reagents. Trichlorosilyl enolates of cyclohexanone (E-enolate) and propiophenone (Z-enolate) reacted readily at room temperature with a wide variety of aldehydes to afford aldoladdition products in high yield and diastereoselectivity (E → syn, Z → anti). These reactions were shown to be
The Chemistry of Trichlorosilyl Enolates. 2. Highly-Selective Asymmetric Aldol Additions of Ketone Enolates
作者:Scott E. Denmark、Ken-Tsung Wong、Robert A. Stavenger
DOI:10.1021/ja9636698
日期:1997.3.1
problem, namely, the invention/discovery of asuitable chiral Lewis acid catalyst to effect the reaction betweenan enoxysilane derivative and an aldehyde, Scheme 1 (X ) Me).In a recent Communication we have described a conceptuallydistinct approach which employs chiral Lewis bases (phos-phoramides) in combination with trichlorosilyl enolates, Scheme1(X)Cl).
Asymmetric Aldol Reaction Catalyzed by a Chiral Phosphine-Silver Complex
作者:Akira Yanagisawa、Ryoji Miyake、Kazuhiro Yoshida
DOI:10.1002/ejoc.201402351
日期:2014.7
A catalytic asymmetricaldolreaction of alkenyl trihaloacetates or a γ,δ-unsaturated δ-lactone with aldehydes or an α-ketoester was achieved by using a 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl·silver trifluoromethanesulfonate complex as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol. Optically active α-alkyl β-hydroxy ketones with enantioselectivities
通过使用 2,2'-双(二苯基膦)-1,1'-联萘·三氟甲磺酸银实现了烯基三卤乙酸酯或 γ,δ-不饱和 δ-内酯与醛或 α-酮酯的催化不对称醛醇反应在甲醇存在下,络合物作为手性预催化剂,N,N-二异丙基乙胺作为碱预催化剂。通过原位生成的手性银烯醇化物,以中等至高产率非对映选择性地获得了对映选择性高达 95% ee 的光学活性 α-烷基 β-羟基酮。
BINAP/AgOTf/KF/18-Crown-6 as New Bifunctional Catalysts for Asymmetric Sakurai−Hosomi Allylation and Mukaiyama Aldol Reaction
A catalytic amount of KF.18-crown-6 complex is effective as a soluble fluoride source to activate an asymmetric Sakurai-Hosomi allylation with BINAP and silver(I) triflate catalyst. The allylation of a variety of aromatic, alpha,beta-unsaturated and aliphatic aldehydes with allylic trimethoxysilane resulted in high yields and remarkable enantioselectivities. In addition, the asymmetric Mukaiyama-type
An efficient dipeptide-catalyzed direct asymmetric aldol reaction of equimolar reactants in solid media
作者:Meng Lei、Shuai Xia、Junfeng Wang、Zemei Ge、Tieming Cheng、Runtao Li
DOI:10.1002/chir.20783
日期:——
The directasymmetricaldolreactions of equivalent molar amounts of aldehydes and ketones were carried out at −20 °C over alkaline Al2O3 with 20 mol % of Pro‐Trp as catalyst and 20 mol % of N‐methylmorpholine or 1,4‐diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work‐up, moderate to high isolated yields (up to 95%), good diastereoselectivities (>99:1), and enantioselectivities