倍半萜生物碱Dendrobine的全合成研究进展

石斛碱(Dendrobine)是一类从传统中药金钗石斛中分离得到的具有Picrotoxane倍半萜碳骨架的生物碱类天然产物.由于该化合物具有多环稠合和七个连续立体中心的结构特点,以及镇痛和退热等药理活性,引起了众多有机合成化学家和药物化学家的关注.五十年来,天然产物Dendrobine的药理活性研究和化学合成不断涌现,...     

乌药烷型倍半萜二聚体Sarcandrolide J及Shizukaol D的全合成

正Angew.Chem.Int.Ed.2017,56,637~640Sarcandrolide J及Shizukaol D是两个具有代表性的[4+2]型乌药烷倍半萜二聚体天然产物,颇具合成挑战性.最近,基于修正的生源合成假说,四川大学化学学院刘波课题组成功实现了Sarcandrolide J及Shizukaol D的首次不对称全合成.以中间体1为原料,分别经11步合成亲双烯体3和呋喃共轭二烯前体6.两片段发生正常电子需求的     

7-表-γ-桉叶油醇的不对称全合成

桉烷型倍半萜类化合物广泛分布于自然界中, 普遍具有昆虫拒食、植物生长调节、细胞生长抑制等生物活性[1～3], 因此, 近年来越来越受到有机化学家的重视. 最近, 法国学者Ramanoelina等[4]从传统药用植物Laggera alata var. Alata Sch. Bip. Ex oliv.中分离得到的两个新的此类化合物: 7-表-γ-桉叶油醇(1)和7-表-β-桉叶油醇(2), 它们的合成均未见报道, 其结构如下式.     

仿生合成:新型苍耳烷倍半萜二聚体的发现

<正>Angew.Chem.Int.Ed.2014,53,14494~14498苍耳烷倍半萜是从药用植物苍耳中发现的一类活性天然产物,其家族成员通常具有顺式或反式5~7双环骨架.另外,自然界中还存在少数苍耳烷倍半萜二聚体,均由顺式单体8-epi-xanthatin经过头-尾(head-to-tail)聚合方式形成.然而,自然界中尚未发现由反式单体xanthatin衍生而来的二聚体.清华大学药学系唐叶峰课题组以xanthatin     

天然产物Iscomene的全合成研究进展

对天然产物Isocoene全合成研究方法进行了综述。分析了各合成路线的关键步 骤，并部分讨论了各方法的优缺点。     

抗疟倍半萜过氧化物全合成进展: 青蒿素和鹰瓜素

综述了鹰瓜素A和青蒿素全合成近年来的进展。     

二倍半萜Bolivianine的仿生全合成

2007年,法国的Jullian课题组从金粟兰科雪香兰属柳兰中提取得到了两种结构复杂的二倍半萜bolivianine和isobolivianine,其独特的含九个手性中心的七环骨架结构及其潜在的生物活性吸引了合成化学家的兴趣.最近,基于修正的生源合成假说,四川大学化学学院刘波课题组成功实现了bolivianine的首次立体选择性全合成.从已知手性源马鞭烯酮出发,经过5步反应生成化合物2.原位制备的烯丙基重氮化物在钯催化下,高立体选择性地发生分子内的环丙烷化反应,构建了目     

抗疟倍半萜过氧化物青蒿素和鹰爪素A的全合成

青蒿素和鹰爪素A是从中药中分离的两个含过氧基团的抗疟活性组分。特别是青蒿素已成为新型的抗疟药物,因而引起合成化学家的极大兴趣。现对该两个化合物的全合成作一综述。     

Thapsigargin的全合成研究进展

Thapsigargin是一类从地中海植物毒胡萝卜(thapsia garganica)中分离得到的结构复杂的高氧化态倍半萜内酯,其对肌浆-内质网Ca~(2+)-ATP泵(SERCAs)具有不可逆的抑制作用,抑制浓度达纳摩尔级别(KD=0.4 nmol/L)。Thapsigargin因其独特的结构和良好的生物活性而备受有机合成化学家的广泛关注。在合成中,立体选择性地构建该分子cis-5/7/5稠环体系以及多个手性中心是极具挑战性的。本文综述了该分子近二十年来的全合成研究进展。     

Synthesis of Carbocycles via Intramolecular Conjugate Additions: Total Syntheses of Axane Sesquiterpenoids

Syntheses of (+/-)-axamide-1 (2) and (+/-)-axisonitrile-1 (1) are described. The syntheses require 12 steps and 13 steps, respectively, from vinylogous ester 8 and feature the diastereoselective cyclization of unsaturated ester 7 to perhydroindan 5. Some interesting reactions of the organometallic derived from [(trimethylsilyl)methyl]magnesium chloride and cerium trichloride are also described.     

Syntheses of Novel Triphenylene-Aminoanthraquinone Dimers and Studies on Their Mesomorphic and Fluorescence Properties

Two novel triphenylene-aminoanthraquinone dimers 4a and 4b were synthesized by reacting triphenylene carboxyl derivatives 3a or 3b with 2-aminoanthracene-9,10-dione in yields of 80% and 78%, respectively. Their structures were confirmed by ¹H NMR, electrospray ionization (ESI-MS), and elemental analysis. Their mesomorphic properties were studied by diffraction scanning calorimetry (DSC), polarizing optical microscopy (POM), and x-ray diffraction (XRD). The mesomorphic results suggested that they possess excellent mesophase properties. The investigation of fluorescence properties indicated that the strong cooperating fluorescence actions exist between two structural units. The fluorescence of dimers 4a and4b are seriously quenched due to the electron transfer from donor (triphenylene unit) to acceptor (aminoanthraquinone unit).     

N-混杂卟啉的合成及其衍生化反应的进展

按N-混杂卟啉的不同合成方法,详细介绍了结构复杂的N-混杂卟啉的合成及各种衍生化反应的进展.     

Asymmetric Total Syntheses of Di‐ and Sesquiterpenoids by Catalytic C−C Activation of Cyclopentanones

To show the synthetic utility of the catalytic C?C activation of less strained substrates, described here are the collective and concise syntheses of the natural products (?)‐microthecaline A, (?)‐leubehanol, (+)‐pseudopteroxazole, (+)‐seco‐pseudopteroxazole, pseudopterosin A–F and G—J aglycones, and (+)‐heritonin. The key step in these syntheses involve a Rh‐catalyzed C?C/C?H activation cascade of 3‐arylcyclopentanones, which provides a rapid and enantioselective route to access the polysubstituted tetrahydronaphthalene cores presented in these natural products. Other important features include 1) the direct C?H amination of the tetralone substrate in the synthesis of (?)‐microthecaline A, 2) the use of phosphoric acid to enhance efficiency and regioselectivity for problematic cyclopentanone substrates in the C?C activation reactions, and 3) the direct conversion of serrulatane into amphilectane diterpenes by an allylic cyclodehydrogenation coupling.     

Sesquiterpenoids and Their Glycosides from Gynura procumbens

Chemical investigation of the MeOH extract of the leaves of Gynura procumbens (Lour .) Merr . afforded one new sesquiterpenoid, muurol‐4‐ene‐1β,3β,10β‐triol ( 1 ), and two sesquiterpene glycosides, muurol‐4‐ene‐1β,3β,10β‐triol 3‐O‐β‐D ‐glucopyranoside ( 2 ) and muurol‐4‐ene‐1β,3β,15‐triol 3‐O‐β‐D ‐glucopyranoside ( 3 ), together with three known sesquiterpenoids. Their structures were elucidated on the basis of spectroscopic analyses and chemical methods.     

Packing Structures of Thiophene Dimers and Their Effects on Excitation Energies of Thiophene Dimers

IntroductionPi(π) conjugated polymers have received exten-sive experimental and theoretical attention because oftheir fascinating electronic and optical properties[1—3].Recently, many new experiment results[4—6]have re-vealed that the inter-chain inter…     

埃博霉素的合成

埃博霉素(Epothilones)是一类新的具有抗癌活性的化合物, 其作用机理与紫杉醇相似。对天然埃博霉素及其衍生物的主要全合成进行了综述.     

Total Syntheses of Sarcandrolide J and Shizukaol D: Lindenane Sesquiterpenoid [4+2] Dimers

The syntheses of members of a family of lindenane sesquiterpenoid [4+2] dimers led to the total syntheses of sarcandrolide J and shizukaol D. Inspired by a modified biosynthetic pathway, a cascade featuring furan formation/alkene isomerization/Diels–Alder cycloaddition was devised to construct the congested polycyclic architecture of the target molecules with the correct stereochemistry. This study presents a pioneering synthetic entry to this family of natural products and paves the way for fully exploring their biological functions.     

Total Syntheses of Tubulysins

The total syntheses of tetrapeptides tubulysins D ( 1 b ), U ( 1 c ), and V ( 1 d ), which are potent tubulin polymerization inhibitors, are described. The synthesis of Tuv ( 2 ), an unusual amino acid constituent of tubulysins, includes an 1,3‐dipolar cycloaddition reaction of chiral nitrone D ‐ 6 derived from D ‐gulose with N‐acryloyl camphor sultam (?)‐ 9 employing the double asymmetric induction, whereas the synthesis of Tup ( 20 ), another unusual amino acid, involves a stereoselective Evans aldol reaction of (Z)‐boron enolate generated from (S)‐4‐isopropyl‐3‐propionyl‐2‐oxazolidinone with N‐protected phenylalaninal and a subsequent Barton deoxygenation protocol. We accomplished the total syntheses of tubulysins U ( 1 c ) and V ( 1 d ) by using these methodologies, in which the isoxazolidine ring was used as the effective protective group for γ‐amido alcohol functionality. Furthermore, to understand the structure‐activity relationship of tubulysins, we synthesized tubulysin D ( 1 b ) and cyclo‐tubulysin D ( 1 e ) from 2 ‐Me and 20 , and ent‐tubulysin D (ent‐ 1 d ) from ent‐ 2 ‐Me and ent‐ 20 , respectively. The preliminary results regarding their biological activities are also reported.     

Total Syntheses of Vancomycin

A total synthesis of the vancomycin aglycon 1 has eluded synthetic chemists for so many years that the preparation of this molecule has become a vendetta for some groups. Finally, and almost simultaneously, research teams led by Evans and by Nicolaou have succeeded. Similarities and differences in their synthetic approaches are highlighted herein.