Metal-catalyzed enantioselective allylation in asymmetric synthesis

Metal-catalyzed enantioselective allylation, which involves the substitution of allylic metal intermediates with a diverse range of different nucleophiles or S(N)2'-type allylic substitution, leads to the formation of C-H, -C, -O, -N, -S, and other bonds with very high levels of asymmetric induction. The reaction may tolerate a broad range of functional groups and has been applied successfully to the synthesis of many natural products and new chiral compounds.     

Synthesis of the mixed acetal segment of S-glyceroplasmalopsychosine

In this report the concept of converting carbohydrate to non-carbohydrate asymmetric molecules has been successfully exploited. The mixed acetal segment of glyceroplasmalopsychosine, a novel glycolipid, has been synthesized in a stereospecific manner using two simple sugar units. The glycosidation reaction between these two monosaccharides ensured the correct acetal stereocenter of the target molecule. Either olefin metathesis or heterogeneous Wittig reactions were used for constructing the long aliphatic chain of glyceroplasmalopsychosine.     

Stereoselective synthesis of the C33-C44 fragment of palau’amide

An efficient stereoselective synthesis of the C33-C44 fragment of palau’amide is described using a Sharpless asymmetric epoxidation, a regioselective nucleophilic ring opening of the epoxide, a Grignard reaction and a Luche stereoselective reduction of a keto compound as the key steps.     

Direct asymmetric aldol reactions catalyzed by nanocrystalline copper(II) oxide

The direct asymmetric aldol reactions of aromatic and heteroaromatic aldehydes with acetone to afford chiral β-hydroxy carbonyl compounds in good yields and good to moderate enantioselectivities are realized using nanocrystalline copper(II) oxide in the presence of (1S,2S)-(−)-1,2-diphenylethylenediamine at −30 °C. The catalyst can be reused for four cycles with consistent activity and enantioselectivity.     

3,6-二氯哒嗪-金鸡纳生物碱衍生物催化不对称“中断的”Feist-Bénary反应的研究

将3,6-二氯哒嗪-金鸡纳生物碱衍生物用于催化β-二羰基化合物与溴乙酰甲酸乙酯/β-取代的溴乙酰甲酸乙酯的不对称“中断的”Feist-Bénary反应, 得到了较高的化学产率(72%～97%)和最高达93% ee的立体选择性.     

新型手性亲核催化剂4-二甲胺基吡啶衍生物的研究进展

手性4-二甲胺基吡啶(DMAP, 4-Dimethylaminopyridine)衍生物作为具有较高催化活性和对映选择性的新型手性亲核催化剂, 已经在多种不对称催化反应中得到应用, 并取得了很好的研究成果. 目前, 手性DMAP衍生物化学的研究正成为催化不对称合成领域中一个十分活跃和引人注目的研究热点. 综述了手性DMAP衍生物化学近几年的研究进展.     

有机催化的不对称氧化反应

有机催化剂在不对称氧化反应中显示出巨大应用潜力. 综述了不同类型的有机催化剂催化的α,β-不饱和醛酮、烯烃的不对称环氧化反应及羰基化合物的不对称α-羟基化反应, 并对催化特点及催化机理作了详细的描述.     

α-氨基膦酸(酯)不对称合成研究进展

α-氨基膦酸作为天然氨基酸的含磷类似物, 具有广泛的生物活性, 详细介绍了使用手性辅助基团诱导和手性催化剂催化两种方法不对称合成光学活性α-氨基膦酸(酯)的最新研究进展.