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1.
N-Boc protected amino acids of analogues of peptide nucleic acid (PNA),which are a class of conformationally constrained building blocks based on 4-aminoproline backbone with chirality at 2-c and 4-c,have been synthesized.Those monomers can be used for the construction of novel peptide nucleic acid analogues. 相似文献
2.
IntroductionAbouttenyearsago ,PNA ,astructuralmimicofDNAinwhichthesugar phosphatebackboneisreplacedbyN (2 aminoethyl)glycine (aeg)linkageemergedasapotentialanti sensetherapeuticagent.1PNAhassomeadvantages:(1)itisstabletocellularnucleasesandproteases,(2 )ithybridizeswithcomplementaryDNAorRNA (cDNA/RNA)sequenceswithhighaffinity ,(3)ithaslownon specificinteractionwithcellularcontentsand (4 )itiseasilysynthesizedbyadoptionofsolidphasepeptidesynthesischemistry .However,thema jorlimitationo… 相似文献
3.
Purakkattle Biju 《合成通讯》2013,43(12):1940-1945
A new methodology is described for the synthesis of α,α-difluorinated ketones by the addition of organolithium reagents to α,α-difluoro-N-methoxy-N-methyl amides (Weinreb amides). 相似文献
4.
Subhradeep Dutta Dr. Jae Hyun Kim Kamal Bhatt Dillon R. L. Rickertsen Dr. Khalil A. Abboud Dr. Ion Ghiviriga Prof. Dr. Daniel Seidel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(1):e202313247
A new strategy to access α-functionalized alicyclic amines via their corresponding imine-BF3 complexes is reported. Isolable imine-BF3 complexes, readily prepared via dehydrohalogenation of N-bromoamines in a base-promoted/18-crown-6 catalyzed process followed by addition of boron trifluoride etherate, undergo reactions with a wide range of organometallic nucleophiles to afford α-functionalized azacycles. Organozinc and organomagnesium nucleophiles add at ambient temperatures, obviating the need for cryogenic conditions. In situ preparation of imine-BF3 complexes provides access to α-functionalized morpholines and piperazines directly from their parent amines in a single operation. α-Functionalized morpholines can be elaborated further, for instance by installing a second substituent in the α′-position. 相似文献
5.
B←N coordination bond can be used to develop polymer electron acceptors for efficient all-polymer solar cells(all-PSCs). Here, we report a new alternating conjugated polymer containing two building blocks based on B←N unit. The polymer exhibits strong light absorption in the visible range, low-lying LUMO/HOMO energy levels and moderate electron mobility. The resulting all-PSC devices exhibit power conversion efficiencies of 1.50%–2.47%. 相似文献
6.
7.
Carsten Schips 《Journal of carbohydrate chemistry》2013,32(8-9):773-788
S‐Glycosyl L‐aspartic acid building blocks were synthesized starting from 1‐thiosugars by reaction with 5‐aminopentanol and suitably protected L‐aspartic acid pentafluorophenyl ester in a one‐pot procedure under Mitsunobu conditions using 1,1′‐azodicarbonyl dipiperidine and trimethyl phosphine. The method allowed for the preparation of S‐glycosyl amino acid building blocks in one step without protection of the amino function for the Mitsunobu condensation. Alternatively, the title compounds were prepared by a stepwise approach via 5‐aminopentyl 1‐thioglycosides. 相似文献
8.
Samia Guezane Lakoud Malika Berredjem Nour-Eddine Aouf 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):762-768
Abstract A new series of modified α-amidophosphonates (or β-ketophosphonate) was synthesized by an efficient method, starting from aminoesters and chloroacetyl chloride. We have established that chloroacetyl chloride is a suitable reagent allowing the introduction a halogen moiety for the Arbuzov reaction. The α-amidophosphonates were prepared in two steps (acetylation, phosphorylation). Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
9.
A synthesis of α-bromo-α,β-unsaturated esters 2 from tert-butyl α-(trimethylsilyl)-α-bromoacetate (1) and carbonyl compounds is described. 相似文献
10.
Abstract The reaction of N-phenyliminoketenylidenetriphenylphosphorane [a] (1), with 2-benzylidene-1, 3-indandione (2), 1,2-diphenyl-3,4-pyrazolidenedione (3)and/or 5-benzylidene barbituric acid (4) has been investigated. When ylide 1 was allowed to react with compounds 2, 3 or 4 in THF at ambient temp. the corresponding new pyrano-phosphoranylidenes 5, 6 or 7 were obtained. The elemental microanalyses, IR, 1H NMR, 31P NMR and MS data agree with the structure of the cyclic iminophosphoranes by [4+2]-cycloaddition and exclude 4-membered ring structure by [2+2]-cycloaddition. When the Wittig reaction was carried on the pyrano-phosphoranes 5, 6 or 7 using p-nitrobenzaldehyde, the exocyclic olefins together with triphenylphosphine oxide were isolated. 相似文献
11.
The reaction of α,α-dichlorobenzyltrimethylsilane with carbonyl compounds in the presence of fluoride ion fails to give reasonable yields of the α,α-dichlorobenzyl adducts except when carried out in the presence of zinc iodide and in HMPA as solvent. Under these conditions moderate yields of the adducts can be obtained with cyclohexanone, cyclohexenone, benzaldhyde and trans cinnamaldehyde. These reactions were compared with those of α,α-dichlorobenzyllithium. 相似文献
12.
Yong WU* Mei GUAN Zheng XU Li Cheng Xiao Chun WU School of Pharmacy Sichuan University Chengdu The First Hospital Sichuan University Chengdu 《中国化学快报》2001,(9)
During the last decade, chiral building blocks for 1, 3-diols of various configurations have been synthesized and applied widely in the total synthesis of natural polyene macrolide antibiotics1 and 1(, 25-dihydroxyvitamin D3 analogues2,3. The synthesis of the building block has attracted much interest in recent years. Herein, we report the synthesis of two chiral building blocks 1 and 2 in 8 steps and 7 steps respectively, starting from the readily available and inexpensive D (+)-xylose 3 as o… 相似文献
13.
Laura Frey Orlando Oliveira Dr. Ashish Sharma Roman Guntermann Soraia P. S. Fernandes Krystal M. Cid-Seara Hosanna Abbay Henry Thornes Prof. João Rocha Dr. Markus Döblinger Dr. Tim Kowalczyk Prof. Akshay Rao Dr. Laura M. Salonen Dr. Dana D. Medina 《Angewandte Chemie (International ed. in English)》2023,62(30):e202302872
A three-component synthesis methodology is described for the formation of covalent organic frameworks (COFs) containing extended aromatics. Notably, this approach enables synthesis of the building blocks and COF along parallel reaction landscapes, on a similar timeframe. The use of fragmental building block components, namely pyrene dione diboronic acid as aggregation-inducing COF precursor and the diamines o-phenylenediamine (Ph), 2,3-diaminonaphthalene (Naph), or (1R,2R)-(+)-1,2-diphenylethylenediamine (2Ph) as extending functionalization units in conjunction with 2,3,6,7,10,11-hexahydroxytriphenylene, resulted in the formation of the corresponding pyrene-fused azaacene, i.e., Aza-COF series with full conversion of the dione moiety, long-range order, and high surface area. In addition, the novel three-component synthesis was successfully applied to produce highly crystalline, oriented thin films of the Aza-COFs with nanostructured surfaces on various substrates. The Aza-COFs exhibit light absorption maxima in the blue spectral region, and each Aza-COF presents a distinct photoluminescence profile. Transient absorption measurements of Aza-Ph- and Aza-Naph-COFs suggest ultrafast relaxation dynamics of excited-states within these COFs. 相似文献
14.
SHA Chin-Kang CHIU Rei-Torng LIH Shinn-Horng SANTHOSH K.C CHANG Ching-Jung TSENG Wei-Hong HO Wen-Yueh 《高等学校化学研究》2001,17(3)
Intramolecular radical cyclization reactions are now used routinely to synthesize carbocyclic and heterocyclic structures. We have reported that α-carbonyl radicals 1, generated from the corresponding iodo ketones or enones, underwent intramolecular radical cyclization smoothly to afford products 2.1, 2,3 相似文献
15.
Since the discovery of the first sulfinatodehalogenation reaction in 1981 1, great efforts havebeen devoted to this useful reaction. The substrates have been expanded fromperfluoroalkyl iodide (R.I) to per- and poly-fluoroalkyl handes (R,X, X = Br, I, R,CCI,),and many sulfinatodehalogenating reagents such as NaZSZO4, HOCH,SO,Na,H,NC(=NH)SO,H and NaZSZO, have been developed=. Recently, thesulfinatodehalogenation of 2,2,2-trifluoroethyl handes was accomplished by Chen et al.'Howev… 相似文献
16.
Astrid Vogt Fabian Schwer Dr. Sebastian Förtsch Christoph Lorenz Dr. Elena Mena-Osteritz Anna Aubele Teresa Kraus Prof. Peter Bäuerle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(48):12362-12370
A novel and versatile method for the N-arylation of dithieno[3,2-b:2′,3′-d]pyrrole (DTP) is presented. By Pd- or Cu-catalyzed coupling a variety of arenes and acenes were directly attached at the DTP−nitrogen yielding a variety of functionalized DTPs. Investigations on optical and redox properties led to valuable structure-property relationships, which were corroborated by quantum chemical calculations. Further functionalization and elongation of the conjugation of an acceptor-substituted DTP was elaborated to result in complex cruciform-type donor−acceptor oligomers, which were investigated and implemented in single material organic solar cells. 相似文献
17.
Dr. Ilia Kochetygov Jocelyn Roth Dr. Jordi Espín Sophia Pache Dr. Anita Justin Till Schertenleib Dr. Nazanin Taheri Dr. Dmitry Chernyshov Prof. Wendy L. Queen 《Angewandte Chemie (International ed. in English)》2023,62(16):e202215595
The design of metal–organic frameworks (MOFs) having large pore sizes and volumes often requires the use of complex organic ligands, currently synthesized using costly and time-consuming palladium-catalyzed coupling chemistry. Thus, in the present work, a new strategy for ligand design is reported, where piperazine and dihydrophenazine units are used as substitutes for benzene rings, which are the basic building block of most MOF ligands. This chemistry, which is based on simple, nucleophilic aromatic substitution (SNAr) reactions, is used for the transition metal catalyst-free construction of 21 new, carboxylate-based ligands with varying sizes, shapes, and denticity and 15 linear di- and tetra-nitriles. Moreover, to demonstrate the utility of the ligands as building blocks, 16 new structurally diverse MOFs having surface areas up to 3100 m2 g−1 were also synthesized. 相似文献
18.
Ch. Syama Sundar D. Srinivasulu S. K. Nayak C. Suresh Reddy 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):523-534
Abstract A green one-pot three-component synthesis has been developed for α-aminophosphonates by condensation of aldehydes, amines, and diethylphosphite by using nonionic surfactant Tween-20 as catalyst in aqueous media. The results showed that this synthetic route for α-aminophosphonates takes just 25–60 min for completion at 60 °C and affords 64%–91% yields depending on the nature of the amine substrates. The major advantages of this novel method are green reaction conditions with water as solvent, simple workup, less reaction times, and high to moderate yields. 相似文献
19.
Ali Ramazani Fatemeh Zeinali Nasrabadi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1214-1219
Abstract The reaction between a thioacid and an α-haloketone in water affords thioester derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed. 相似文献
20.
Pei Pei SUN* Ya Ping XIAO Bao Chuan SHI Department of Chemistry Nanjing Normal University Nanjing 《中国化学快报》2000,11(12)
Organic reactions promoted by active metals have aroused much interest in recent years. Active bismuth has been used in Barbier-type reaction of allylic halides with aldehydes1 and aldimines2 as well as Reformatzky type reaction3. Other publications referred to the cross coupling between aldehydes and α-diketones4, the substitution to benzotriazole drivatives5 and the reductive coupling reaction of nitro compounds6. These reactions generally promoted by elemental bismuth generated in situ fr… 相似文献