Mesembrine合成方法综述

蕃杏科生物碱Mesembrine由Bodendorf研究小组于1957年从Mesembryanthemum tortuosum中分离得到.由于其结构特征和有趣的生物活性引起大量的关注.在过去的40年间,该化合物成为合成有机化学感兴趣的目标分子之一.到目前为止,文献中报道的全合成和形式合成路线已有40多种.对其中的31种全合成及形式合成路线进行了综述.     

(±)-Hongoquercin A全合成:可见光促进有机催化多烯环化策略

报道了天然产物分子(±)-Hongoquercin A的仿生全合成路线.作者最近开发了在可见光促进下以染料分子曙红为光敏剂的自由基多烯环化反应.以此为基础,将该方法学应用于(±)-Hongoquercin A全合成中的关键步,一步构建该天然产物分子的多环骨架结构,共7步实现了其全合成.     

α-羟酮重排产物的结构

一叶萩碱由植物一叶萩中分得,六十年代初确定它的化学结构为1.1967年日本Horii等报道了外消旋一叶萩碱的全合成,当时本所鲁桂琛等对一叶萩碱的全合成也进行了探讨,并合成了中间体α-羟酮4.作者通过降解一叶萩碱亦得到4.     

Hetisine型C_(20)二萜生物碱绣线菊碱Ⅳ和Ⅺ的全合成

正以抗心律失常药关附甲素为典型代表的hetisine型C_(20)二萜生物碱具有丰富多样的生物活性和复杂的化学结构,数十年来一直是有机合成化学研究的热点,很多国际上著名的全合成小组相继进行了全合成研究.基于目前对C_(20)二萜生物碱的合成研究,hetisine型C_(20)二萜生物碱全合成的挑战在于C(14)—C(20)键和C(6)—N键的构建.重庆大学     

天然三尖杉碱((-)-Cephalotaxine)的不对称全合成研究

三尖杉碱[(-)-Cephalotaxine]是抗肿瘤天然药物高三尖杉酯碱(Homoharringtonine,HHT)的母核结构,近年来有关结构独特的天然三尖杉碱不对称全合成研究工作不断涌现.综述了1994年以来天然三尖杉碱的不对称全合成研究策略和方法,特别是近几年来的新进展.     

氧化偶联策略在复杂吲哚生物碱全合成中的应用

氧化偶联反应作为一种高效、经济的C—C键构建策略,在天然产物的全合成中得到了重要的应用.近年来,马大为课题组通过发展高效的LiHMDS/I2偶联条件,成功实现了四种复杂吲哚生物碱的全合成,在该领域取得了重要的进展.本文就马大为课题组近年在该领域的工作作一亮点评述.     

番荔枝内酯的全合成研究进展

番荔枝内酯具有独特的化学结构和较强的抗肿瘤活性. 综述了近几年来这类天然产物的全合成研究进展.     

Julia烯烃合成法在天然产物全合成中的应用新进展

Julia烯烃合成法可通过使用不同芳杂基砜和控制反应条件等方法改变反应活性,提高反应立体选择性,从而使其在天然产物的全合成中得到重要的应用.综述了近年来Julia烯烃合成法(包括Julia-Lythgoe反应;Modified-Julia反应;Julia-kocieński反应)在天然产物全合成中的应用进展.     

亮点介绍

正Ir-催化不对称全合成吲哚生物碱(-)-Communesin F J.Am.Chem.Soc.2017,139,3364~3367吲哚生物碱Communesin家族是八个具有复杂七环系的天然产物.因具有独特的化学结构(四个氮原子构成罕见的上下两个aminal基团,外加两个连续手性季碳)和有趣的生物活性而成为明星分子,尤其是Communesin F的全合成备受化学家青睐,包括我国秦勇、马大为研究组在内有五个著名研究组报道过全合成.完成Communesin F这样高     

全合成先锋霉素的重要中间体—噻嗪酸酯的研究

近年来对于先锋霉素全合成的研究有了很大的发展.已报道的全合成路线中,以Merck-Syntex^[1]路线比较实用.为了合成先锋霉素的重要中间体——噻嗪酸酯3,Merck-Syntex使用了Wittig反应,步骤比较长.他们所以采用Wittig反应,是考虑到酯基旁边的α-H不够活泼,不能与甲基酮起缩合反应.     

Recent advances of desymmetrization protocol applied in natural product total synthesis

Desymmetrization synthesis strategy has simplified and improved the efficiency of synthesis, which attracted great attention in the past few decades. Since the strategy has been developed rapidly and got a wide range of applications in natural product total synthesis, the rules are urgent to be summarized. In this Letter, the recent developments of desymmetrization protocol in natural product total synthesis were summarized.     

Development of a Fully Continuous-Flow Approach Towards Asymmetric Total Synthesis of Tetrahydroprotoberberine Natural Alkaloids

Continuous flow synthetic technologies had been widely applied in the total synthesis in the past few decades. Fully continuous flow synthesis is still extremely focused on multi-step synthesis of complex natural pharmaceutical molecules. Thus, the development of fully continuous flow total synthesis of natural products is in demand but challenging. Herein, we demonstrated the first fully continuous flow approach towards asymmetric total synthesis of natural tetrahydroprotoberberine alkaloids, (−)-isocanadine, (−)-tetrahydropseudocoptisine, (−)-stylopine and (−)-nandinine. This method features a concise linear sequence involving four chemical transformations and three on-line work-up processing in an integrated flow platform, without any intermediate purification. The overall yield and enantioselectivity of this four-step continuous flow chemistry were up to 50 % and 92 %ee, respectively, in a total residence time of 32.5 min, corresponding to a throughput of 145 mg/h.     

Enantioselective total synthesis of guanacastepene N using an uncommon 7-endo Heck cyclization as a pivotal step

A convergent, enantioselective total synthesis of (+)-guanacastepene N was developed that features a 7-endo Heck cyclization as the key step. In the course of this synthesis, short syntheses of the enantiomerically pure cyclopentenone and cyclohexene building blocks 5 and 6, which constitute A and C ring fragments of guanacastepene N, were developed. These fragments were linked by a challenging conjugate addition reaction that also generated the C11 quaternary carbon stereocenter. Regioselective 7-endo Heck cyclization gave rise to a tricyclic intermediate, which was elaborated to complete the first total synthesis of guanacastepene N and the second enantioselective total synthesis of a guanacastepene natural product.     

Synthetic studies of cyclic peptides stephanotic acid methyl ester,celogentin C,and moroidin

An account of the total synthesis of stephanotic acid methyl ester and celogentin C is presented. The present synthesis features a tandem asymmetric Michael addition/bromination sequence for the synthesis of leucine-tryptophan moiety, and an oxidative coupling reaction to form the tryptophan-imidazole linkage. Moreover, the total synthesis of moroidin had also been studied, and three different synthetic strategies for the construction of the right-hand ring of moroidin were studied.     

Evolution of a protecting-group-free total synthesis: studies en route to the neuroactive marine macrolide (-)-palmyrolide A

A full account of our synthetic work toward the first total synthesis of the neuroactive marine macrolide (-)-palmyrolide A is described. Our first-generation approach aimed to unlock the unknown C(5)-C(7) stereochemical relationship via the synthesis of four diastereomers of palmyrolide A aldehyde, a known degradation product. When these efforts provided inconclusive results, recourse to synthesizing all possible stereocombinations of the 15-membered macrolide was undertaken. These studies were critical in confirming the absolute stereochemistry, yielding the first total synthesis of (+)-ent-palmyrolide A. Subsequent to this work, the first protecting-group-free total synthesis of natural (-)-palmyrolide A is also reported.     

紫杉醇全合成

评论了紫杉醇合成了合成战略，合成路线，逆合成分析及展望，参考文献９篇。     

First total synthesis of the β-carboline alkaloids trigonostemine A,trigonostemine B and a new synthesis of pityriacitrin and hyrtiosulawesine

The total synthesis of four natural products, trigonostemine A, trigonostemine B, pityriacitrin, and hyrtiosulawesine was accomplished. The key intermediates, variously substituted 1-formyl-β-carbolines, were prepared in five steps via a novel synthetic approach using readily available starting materials. These formyl derivatives were then further transformed, providing a general route for the synthesis of the four title alkaloids. The method reported herein represents the first total synthesis of the two trigonostemines and a new pathway to pityriacitrin and hyrtiosulawesine.     

利用一个通用的方法全合成Fuscinarin和Fuscins

通过一个共同的中间体6,首次全合成了fuscinarin (1)和全合成了fuscins,它们都是戊烯酮(pentaketide)的代谢物,在亲近闪烁检测(scintillation proximity assay)中显示具有抗CCR5的活性。这一合成主要是利用微波辅助的 ortho-Claisen/Cope 重排的串联反应更合成中间体10。     

Total synthesis of bryostatins: the development of methodology for the atom-economic and stereoselective synthesis of the ring C subunit

Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for the stereoselective assembly of the ring C subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the ring C subunit of bryostatins.     

Total synthesis of ent-(−)-azonazine using a biomimetic direct oxidative cyclization and structural reassignment of natural product

A biomimetic approach has been investigated and developed for the total synthesis of azonazine, an unusual marine natural cyclopeptide containing a rigid transannular 10-membered ring. A hypervalent iodine-mediated direct oxidative cyclization was successfully developed and applied to construct the highly strained core, which was the key step in the first total synthesis of ent-(−)-azonazine. Based on the physical evidences of synthesized diastereomer and enantiomer of azonazine, both the relative and absolute configurations of the natural product were revised. Two fluorinated azonazine derivatives were also synthesized in short convenient steps utilizing the same intermediate in this work. The established total synthesis opens a potential opportunity to study the structure–activity relationship of natural azonazine.