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1.
The total synthesis of maremycins A, B, C1/C2, D1, and D2 is achieved starting from the natural amino acids l-isoleucine and S-methyl-l-cysteine, in which the total synthesis of maremycins B, C1/C2, and D2 is accomplished for the first time. The synthesis features a position-selective intramolecular bromination process for the synthesis of key chiral building block, a Pd-catalyzed indole synthesis for the preparation of (2S,3S)-β-methyltryptophan and hydroxylation of oxindoles by molecular oxygen. In addition, the protocol for conversion of maremycins A and B to maremycins C and D was improved. 相似文献
2.
Indole 2,5-diketopiperazines (DKPs) are an important type of metabolic cyclic dipeptides containing a tryptophan (Trp) unit possessing a range of interesting biological activities. The intriguing structural features and divergent activities have stimulated tremendous efforts towards their efficient synthesis. Herein, we report the development of a unified strategy for the synthesis of three Trp-containing DKPs, namely tryprostatin A, and maremycins A and B, via a sequential C–H activation strategy. The key Trp skeletons were synthesized from the inexpensive, readily available alanine via a Pd(ii)-catalyzed β-methyl C(sp3)–H monoarylation. A subsequent C2-selective prenylation of the resulting 6-OMe-Trp by Pd/norbornene-promoted C–H activation led to the total synthesis of tryprostatin A in 12 linear steps from alanine with 25% overall yield. Meanwhile, total syntheses of maremycins A and B were successfully accomplished using a sequential Pd-catalyzed methylene C(sp3)–H methylation as the key step in 15 linear steps from alanine.Indole 2,5-diketopiperazines (DKPs) are an important type of metabolic cyclic dipeptides containing a tryptophan (Trp) unit possessing a range of interesting biological activities. 相似文献
3.
Yingxia Lan Yi Zou Tingting Huang Xiaozheng Wang Nelson L. Brock Zixin Deng Shuangjun Lin 《中国科学:化学(英文版)》2016,59(9):1224-1228
The maremycin biosynthetic gene cluster has been identified in Streptomyces sp. B9173. Comparative metabolic profiling with knockout mutant strains led to the identification of new products correlated to the maremycin biosynthesis, in particular the “demethyl”-maremycins with an unexpected D-tryptophan unit. A biosynthetic pathway for the maremycins is proposed and plausible reasoning for tryptophan epimerization in the demethylmaremycin biosynthesis is also provided. 相似文献
4.
Nicolaou KC Rodríguez RM Mitchell HJ Suzuki H Fylaktakidou KC Baudoin O van Delft FL 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(17):3095-3115
In this first of a series of four articles we introduce everninomicin 13,384-1 (1), a powerful antibiotic effective against drug resistant bacteria, as a target for total synthesis and discuss its retrosynthetic analysis. From the three defined fragments required for the synthesis (2: A1B(A)C fragment; 4: DE fragment; 5: FGHA2 fragment), we describe herein two approaches to the A1B(A)C block. The first strategy relied on an olefin metathesis reaction to construct a common intermediate for rings B and C, but was faced with final protecting group problems. The second, and successful approach, involved a 1,2-phenylsulfeno migration and a sulfur directed glycosidation procedure to link rings B and C, as well as an acyl fluoride intermediate to install the sterically hindered aryl ester moiety (ring A1). The final stages of the synthesis of the required 2-phenylseleno glycosyl fluoride 2 required introduction of a phenylseleno group at C-1 of ring C followed by a novel, DAST-promoted 1,2-migration to produce the desired 2-beta-phenylseleno glycosyl fluoride moiety. 相似文献
5.
A. O. Martirosyan S. P. Gasparyan V. E. Oganesyan G. K. Arutyunyan V. V. Martirosyan M. V. Aleksanyan 《Russian Journal of Organic Chemistry》2006,42(12):1786-1788
A procedure has been developed for the synthesis of 2,4-substituted 3-oxo-1-phenylcyclopentan-1-carboxylic acids, and substituent effects on particular steps of the synthesis have been studied. 相似文献
6.
Andersen D Storz T Liu P Wang X Li L Fan P Chen X Allgeier A Burgos A Tedrow J Baum J Chen Y Crockett R Huang L Syed R Larsen RD Martinelli M 《The Journal of organic chemistry》2007,72(25):9648-9655
Melanin-concentrating hormone (MCH) is implicated in the feeding behavior in mammals affording a potential target to control overeating in people. Compound 1 (AMG 076) has been identified as a potent MCHr1 antagonist for the treatment of obesity. A synthesis suitable for the large-scale preparation of this lead candidate was developed to support preclinical studies. A Robinson annulation of benzylpiperidone and resolution of the desired enone from a mixture of the diastereomers afforded key intermediate 6 after a stereoselective hydrogenation. Subsequent Fischer indole synthesis with hydrazine 5 then provided the advanced intermediate, indole 2. Two complementary reductive amination strategies employing either aldehyde 3 or lactol 4 led to the synthesis of title compound 1. 相似文献
7.
Kleinbeck F Fettes GJ Fader LD Carreira EM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3598-3610
A convergent synthesis of bafilomycin A(1), a potent inhibitor of V-type ATPases, is presented. The synthesis relies on the zinc triflate mediated diastereoselective addition of a complex enyne to a sensitive aldehyde as the key fragment coupling. A ruthenium-catalyzed trans-reduction of the resulting propargylic enyne efficiently installs the required C10-C13 trans,trans-diene subunit, implementing an alternative strategy to traditional palladium-catalyzed cross-coupling strategies. A highly selective oxidation of a secondary hydroxyl group in a triol sets the stage for the completion of the synthesis. 相似文献
8.
An efficient and readily modifiable synthesis of GEX1A/herboxidiene/TAN-1609 ( 1) was developed. This modular synthesis featured a Suzuki coupling to install the conjugated diene and a Ru-catalyzed lactonization and Roush crotylation to construct the functionalized tetrahydropyran moiety. Myers' alkylation, cross-metathesis, and Keck crotylation were employed for assembly of the biologically essential side-chain domain. 相似文献
9.
A concise and efficient total synthesis of arizonins B1 and C1 is reported. A key building block alkyne is synthesized from d-glucono-δ-lactone and used in the Dötz benzannulation reaction to construct the naphthalene unit. An oxa-Pictet–Spengler reaction gave the pyran ring while an H2SO4 mediated isomerization set the correct stereochemistry of the target molecules. Alternatively, a direct anti-pyran stereochemistry was prepared in a TFA solvent. The synthesis is competitive to previous reports and marks the first enantioselective synthesis of arizonin B1. 相似文献
10.
[reaction: see text] Total synthesis of hyacinthacine A(1) and its epimer at C3 is described. The synthesis includes a stereocontrolled carboazidation of a chiral allylsilane as a key step. C-Si bond oxidation and reduction of the azide, with ring-closure, complete the total synthesis, which establishes the absolute configuration of 3. 相似文献
11.
Wan YS Chau JL Gavriilidis A Yeung KL 《Chemical communications (Cambridge, England)》2002,(8):878-879
A zeolite-based microengineered reactor was fabricated and tested for 1-pentene epoxidation over titanium silicalite-1 (TS-1) catalyst, which has been selectively incorporated within the microreactor channel using a new synthesis procedure. 相似文献
12.
A simple, novel, and efficient route for the synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 has been devised. Preparation of pyrazole bromide 3 from potassium tricyanomethanide can be accomplished in only two steps in good yield and features a selective Sandmeyer reaction on the corresponding diaminopyrazole. This allows for a more versatile synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 than was previously possible. 相似文献
13.
Ryabukhin SV Plaskon AS Volochnyuk DM Shivanyuk AN Tolmachev AA 《The Journal of organic chemistry》2007,72(19):7417-7419
A convenient one-pot method for the synthesis of 2,3-dihydro-1H-benzimidazoles has been elaborated. A set of 2,3-dihydro-1H-benzimidazoles was prepared from various ortho-dialkylaminoanilines and aldehydes using Me3SiCl as a condensation agent and pyridine as a basic medium. 相似文献
14.
Shakhmaev R. N. Ignatishina M. G. Zorin V. V. 《Russian Journal of General Chemistry》2020,90(7):1365-1367
Russian Journal of General Chemistry - A stereoselective method has been developed for the synthesis of (1E)-chloroalk-1-en-4-ynes, promising precursors to 1,4-enynes, on the basis of alkynylation... 相似文献
15.
Scarlato GR DeMattei JA Chong LS Ogawa AK Lin MR Armstrong RW 《The Journal of organic chemistry》1996,61(18):6139-6152
We report our synthesis of the C(1)-C(25) fragment of serine/threonine phosphatase PP1 and PP2A inhibitor, calyculin C. Synthetic efforts were directed initially toward the synthesis of a spiroketal core fragment (7), which culminated in completion of the bottom half of the natural product. The synthesis of fragment 7 and subsequent elaboration relied on an allylboration strategy for introduction of chirality. The C(1)-C(8) fragment representing the potentially unstable tetraene moiety was introduced as a separate entity. 相似文献
16.
Babak Kaboudin 《Tetrahedron letters》2003,44(5):1051-1053
A simple, efficient, and general method has been developed for the synthesis of 1-aminophosphonates from 1-hydroxyphosphonates under solvent-free conditions using microwave irradiation. 1-Aminophosphonates were obtained in high yield and mild conditions by reaction of diethyl 1-hydroxyalkylphosphonates with amines in the presence of acidic alumina. 相似文献
17.
Paul S. Humphries Gayatri Balan Bruce M. Bechle Edward L. Conn Kenneth J. Dirico Yu Hui Robert M. Oliver James A. Southers Xiaojing Yang 《Tetrahedron letters》2009,50(18):2140-806
We have developed a number of efficient protocols for the facile synthesis of 1,2,3,4-tetrahydroisoquinolin-1-ones. This synthetic methodology allowed concise and efficient exploration of the SAR in all areas of the molecule. A number of these methods proved to be versatile, efficient and amenable to parallel synthesis. 相似文献
18.
[reaction: see text] A brief stereospecific synthesis of cryptophycin 1 is described in which (R)-mandelic acid serves as the sole source of asymmetry for unit A. The key step is a hetero-Diels-Alder cycloaddition. 相似文献
19.
ThedidenlnaketalsAandBhaveprovedtobesignificantinhibitorstoHIV-Iprotease'.UPtotilepresent.however,nosuccessfulsynthesishasbeenreported.Inconnectiollx'l,lthOLlrs}'ntheticstudiesoftheiranalogLles,wehavereportedasuccesslillsynthesisofthesimilarilltermediateof32.Hereinwewouldpresentanefficientprocedureforthediastereoselectivesynthesisofanotherintermediate4.Basedoiltileretrosyntheticanalysis,theintermediate4couldbesynthesizedfromllaturalI.-(-)-nlelltllollebecauseofthevaltlablechiralCSmethyl.… 相似文献
20.
I. B. Dzvinchuk A. M. Nesterenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2010,46(1):66-71
A method of synthesis is proposed for previously unknown 3,5-diaryl-4-(1H-imidazol-2-yl)-1H-pyra-zoles based on the thermal
intramolecular cyclocondensation of aroylhydrazones of 2-phenacyl-1H-imidazole. 相似文献