Enantioselective Synthesis of Planar-Chiral Phosphaferrocenes by Molybdenum-Catalyzed Asymmetric Interannular Ring-Closing Metathesis

Abstract

Enantioselective synthesis of planar-chiral phosphaferrocenes was realized for the first time by molybdenum-catalyzed asymmetric ring-closing metathesis (ARCM) in up to 99% ee, which is the first application of ARCM to induction of chirality in molecules devoid of stereogenic centers.

Double Friedel–Crafts Acylation Reactions on the Same Ring of a Metallocene: Synthesis of a 2,5‐Diacetylphospharuthenocene

“…The area is interesting because, in addition to the fundamental role of electrophilic aromatic substitutions in the preparation of new phosphametallocene‐based ligands (e.g., 3 , 4 and related structures for enantioselection; Scheme ),20–30 the possibility of using the phosphorus atom as an “organising site” to allow carbon atoms of the phospholyl ring to be distinguished and elaborated selectively is appealing, particularly if sequential substitutions on the same ring can be effected (Scheme ). Here we show that 2,5‐diacylations at the phospholyl ring can be achieved easily and examine the factors that make them viable.…”

Research Progress on the Synthesis and Application of Cyclopentadiene Derivatives

“…图式 10 二茂钌衍生物的合成 Scheme 10 Synthesis of ruthenocene derivatives 在众多方法中 [59,60] , 通过直接催化 C-H 键活化可 合成不同的茂金属配合物, 此方法是合成不对称金属茂 化合物有效的方法 [61] . 1997 先与环戊二烯发生 Diels-Alder 反应生成极不稳定的环 状过氧化中间产物, 此化合物在温度高于 0 ℃时即发 生 Claisen 重排转化成烯酮化合物(Scheme 11).…”

Recent Advances in Transition-Metal-Catalyzed Enantioselective Syntheses of Planar Chiral Ferrocenes

“…Yield 53%~81% racemic (8) 2013 年, 游书力、顾庆等 [21] 2014 年, 游书力课题组 [27] 报道了零价钯催化的分 子内不对称 C-H 键芳基化反应直接构筑平面手性二茂 铁衍生物的研究结果. 他们以(R a )-BINAP 为手性配体、 Pd(OAc) 2 为催化剂、碳酸铯为碱、特戊酸为添加剂, 以 高达 99%的收率和 ee 值, 成功合成了平面手性二茂铁 衍生物.…”