决明和Prosopis物种的顺式 -2-甲基-6-取代的哌啶-3-醇生物碱很容易通过结合氮杂-Achmatowicz 氧化重排和二氢吡啶酮还原,然后将立体选择性烯丙基硅烷加成到N-磺酰亚胺离子上来制备。还原反应的立体化学结果可归因于假轴取向的2,6-取代基和赤道接近的氢化物试剂之间的空间位阻,这解释了通过氢化物的轴向接近而排他地形成顺式醇。通过催化还原除去( E )-甲基-戊-3-烯酸酯侧链中存在的不饱和度,并将剩余的酯基转化为相应的Weinreb's酰胺。该关键中间体用于合成阿齐米酸、脱氧卡辛、酪氨酸和香料。( S )-N-甲苯磺酰氨基呋喃16的简便制备及其向手性 Achmatowicz 氧化产物18 的转化提供了这些生物碱的正式手性合成。
Highly enantioselective Rh-catalyzed transfer hydrogenation of N-sulfonyl ketimines
作者:Se Hun Kwak、Sun Ah Lee、Kee-In Lee
DOI:10.1016/j.tetasy.2010.04.047
日期:2010.4
species comprising N-sulfinyl and N-sulfonyl ketimine, oxime, and enamine derivatives were subjected to asymmetric transferhydrogenation in an azeotropic mixture of formic acid/triethylamine. Among them, the Rh-catalyzed transferhydrogenation of N-sulfonyl ketimine afforded the corresponding 1-arylalkylamines in excellent yield and with high enantioselectivity.
An efficient preparation of optically active α-furfuryl amide by kinetic resolution using the modified sharpless asymmetric epoxidation reagents
作者:Wei-Shan Zhou、Zhi-Hui Lu、Zhi-Min Wang
DOI:10.1016/s0040-4020(01)86343-2
日期:1993.3
Kineticresolution of α-furfuryl amide was first carried out by using the modified Sharpless asymmetric epoxidation reagent to give the slow-reacting enantiomers, (S)-1a–h and (R)-1b,f in high enantioselectivity(90–100% e.e) and high chemical yield (45–50%). Similar results were obtained from the fast-reacting enantiomers. This kineticresolution exhibits the reversed enantioselectivity.
An efficient preparation of optically active α-furfuryl amide by kinetic resolution using the modified sharpless asymmetric epoxidation reagent
作者:Wei-Shan Zhou、Zhi-Hui Lu、Zhi-Min Wang
DOI:10.1016/0040-4039(91)80360-i
日期:1991.3
Kineticresolution of α-furfuryl amide was first carried out by using the modified Sharpless asymmetric epoxidation reagent to give the slow-reacting enantiomers, (S)-1a–f and (R)-1b,f in high enantioselectivity (90–100% e.e) and high chemical yield (45–50%).
Catalytic Environmentally Friendly Protocol for Achmatowicz Rearrangement
作者:Zhilong Li、Rongbiao Tong
DOI:10.1021/acs.joc.6b00469
日期:2016.6.3
The increasing interest in Achmatowiczrearrangement in organic synthesis calls for a more environmentally friendly protocol since the most popular oxidants m-CPBA and NBS produced stoichiometric organic side product (m-chlorobenzoic acid or succinimide). Mechanism-guided analysis enables us to develop a new catalytic method (Oxone/KBr) for AchR in excellent yield with K2SO4 as the only side product
由于最流行的氧化剂m -CPBA和NBS产生化学计量的有机副产物(m-氯苯甲酸或琥珀酰亚胺),因此有机合成中对Achmatowicz重排的兴趣日益增加,这要求采用更加环保的方案。机理指导的分析使我们能够开发出一种新的催化方法(Oxone / KBr),以K 2 SO 4作为唯一的副产物,具有极高的收率,极大地促进了纯化。该协议已与其他转换集成在一起,从而可以快速访问高度功能化的二氢吡喃酮。