已开发出对苯并[ a ]-和吲哚并[2,3- a ]喹啉联苯胺的对映选择性两步法。它由(i)外消旋或前手性δ-氧代(二)酯与(S)-(3,4-二甲氧基苯基)丙氨醇或(S)-色氨酸的立体选择性环缩合反应涉及动态动力学拆分和/或对映体或非对映体酯基的区分,和(ii)随后利用所得恶唑并哌啶酮内酰胺中存在的被掩蔽的N-酰基亚氨基亚胺离子在芳环上进行立体控制环化。
A straightforward procedure for the synthesis of enantiopure polysubstituted piperidines is reported. It involves the direct generation of chiral non-racemic oxazolo[3,2-a]piperidone lactams that already incorporate carbon substituents on the heterocyclic ring and the subsequent removal of the chiralauxiliary. The key step is a cyclocondensation reaction of (R)-phenylglycinol or other amino alcohols
Biogenetically Inspired Enantioselective Approach to Indolo[2,3-<i>a</i>]- and Benzo[<i>a</i>]quinolizidine Alkaloids from a Synthetic Equivalent of Secologanin
作者:Oriol Bassas、Núria Llor、Maria M. M. Santos、Rosa Griera、Elies Molins、Mercedes Amat、Joan Bosch
DOI:10.1021/ol0505609
日期:2005.7.1
oxodiester 1 undergoes stereoselective cyclocondensation with (S)-tryptophanol, (S)-(3,4-dimethoxyphenyl)alaninol, or the corresponding amino acids, in a process involving a tandem dynamic kinetic resolution/desymmetrization of diastereotopic groups, to give bicyclic lactams, which are cyclized to substituted indolo[2,3-a]- and benzo[a]quinolizidines.
Enantioselective Formal Synthesis of (+)-Dihydrocorynantheine and (−)-Dihydrocorynantheol
作者:Mercedes Amat、Arantxa Gómez-Esqué、Carmen Escolano、Maria M. M. Santos、Elies Molins、Joan Bosch
DOI:10.1021/jo802387c
日期:2009.2.6
involving oxidation to an aldehyde, dehydration of the corresponding oxime, and reductive decyanation of the resulting α-aminonitrile, has been developed. The preparation of indoloquinolizidine 27 represents a formal total synthesis of (+)-dihydrocorynantheine, (−)-dihydrocorynantheol, and other indolo[2,3-a]quinolizidine and oxindole alkaloids bearing the same substitution pattern.
据报道,存在于众多吲哚生物碱中的3-乙基吲哚并[2,3- a ]喹唑烷部分的对映选择性结构,关键步骤是(S)-色氨酸与适当的外消旋δ-氧酸酯和区域-和-区域的立体选择性环缩合。内酰胺羰基上的恶唑并哌啶酮的立体选择性环化。已经开发出一种新的除去羟甲基辅助基团的方法,该方法包括氧化成醛,相应的肟脱水以及所得的α-氨基腈还原性脱氰。吲哚并喹唑啉27的制备代表了(+)-二氢红ry烷,(-)-二氢红ry酚和其他吲哚[2,3- a]的正式全合成。] quinolizidine和oxindole生物碱具有相同的取代方式。
Highly enantioselective dynamic kinetic resolution and desymmetrization processes by cyclocondensation of chiral aminoalcohols with racemic or prochiral δ-oxoacid derivatives
作者:Mercedes Amat、Oriol Bassas、Miquel A. Pericàs、Mireia Pastó、Joan Bosch
DOI:10.1039/b413937b
日期:——
Cyclocondensation reactions of aminoalcohols and with racemic or prochiral delta-oxoacid derivatives provide polysubstituted lactams with high enantioselectivity in a process that involves dynamic kinetic resolution and/or desymmetrization of enantiotopic or diastereotopic ester groups.
Several synthetic routes to 3-acetonyl- and 3-(2-oxoethyl)glutarates 1–5 have been explored. The most advantageous involves, as the key steps, the conjugate addition of an appropriately substituted vinylmagnesium bromide to an alkylidenemalonicester, a bis-homologation of the resulting diester and, finally, the reductive ozonolysis of the carbon–carbon double bond. The synthesis can be satisfactorily