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1.
Simon N. Smith Dr. Ryan Craig Prof. Stephen J. Connon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(59):13378-13382
The first divergent synthesis of both γ-amino acid and γ-lactam derivatives from meso-glutaric anhydrides is described. The organocatalytic desymmetrisation with TMSN3 relies on controlled generation of a nucleophilic ammonium azide species mediated by a polystyrene-bound base to promote efficient silylazidation. After Curtius rearrangement of the acyl azide intermediate to access the corresponding isocyanate, hydrolysis/alcoholysis provided uniformly high yields of γ-amino acids and their N-protected counterparts. The same intermediates were shown to undergo an unprecedented decarboxylation–cyclisation cascade in situ to provide synthetically useful yields of γ-lactam derivatives without using any further activating agents. Mechanistic insights invoke the intermediacy of an unconventional γ-N-carboxyanhydride (γ-NCA) in the latter process. Among the examples prepared using this transformation are 8 APIs/molecules of considerable medicinal interest. 相似文献
2.
Aarón Gutiérrez Collar Dr. Cristina Trujillo Bruce Lockett-Walters Dr. Brendan Twamley Prof. Stephen J. Connon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(30):7275-7279
An anion-binding approach to the problem of preparing enantioenriched γ-lactams from enolisable anhydrides and imines is reported. A simple bisurea catalyst promotes the cycloaddition between α-aryl succinic anhydrides and either PMP- or benzhydryl-protected aldimines to provide γ-lactams with two contiguous stereocentres (one quaternary) with complete diastereocontrol and high to excellent enantioselectivity for the first time. A DFT study has provided insight into the catalyst mode of action and the origins of the observed stereocontrol. 相似文献
3.
Kuramshin A. I. Kuramshina E. A. Cherkasov R. A. 《Russian Journal of General Chemistry》2004,74(6):864-872
Photochemical and thermochemical activation were used to prepare new -complexes of chromium, molybdenum and tungsten containing 2- and 4-coordinated methyl acrylate, methyl cynnamate, and dimethyl fumarate molecules. Geometric, electronic, and energetic parameters of the coordinated ester molecules were found and factors governing 2- and 4-coordination of the oxodiene system were revealed by nonempirical calculations. Monocarboxylic acid esters incorporated in the -complexes react with dialkyl hydrogen phosphites to give dialkyl acyl phosphites coordinated with the metal center and susceptible to oxidation the corresponding phosphates. In this case, the phosphorylation involves the OH-tautomer of dialkyl hydrogen phosphite. Coordinated dimethyl fumarate undergoes phosphorylation by two concurrent pathways, viz. transesterification or Pudovik reaction. In the latter case, fragmentation of the organometallic compound takes place. 相似文献
4.
《合成通讯》2013,43(5):745-750
Abstract The reaction of enamines with ethyl diazoacetate (EDA) catalyzed by dirhodium and copper complexes provided γ‐keto esters in good yields. The influences of catalyst, reaction solvent, temperature, and structure of enamines on this transformation were investigated. 相似文献
5.
In search of novel γ-lactam antibacterial agents as non-β-lactam mimics of some γ-lactam antibiotics, N-aryl modification in the γ-lactam ring has been made to synthesize compounds 4–8 in two to six steps. Compound 4 was synthesized using the intermolecular Michael addition of diethyl N-(6-coumarinyl)-2-aminomalonate and 3-aryl/(2-heteroaryl)acryloyl chloride followed by intramolecular amidification. Hydrolysis and stereoselective decarboxylation of 4 resulted in the formation of trans- γ-lactam carboxylic acids (5), which on side chain homologation followed by saponification of the intermediate γ-lactam monoester (7) afforded γ-lactam carboxylic derivatives 8. Moderate to good bacterial growth inhibition was observed for some of the synthesized compounds against E. coli and S. aureus. 相似文献
6.
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
7.
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
8.
Wei DENG Ye Feng WANG Lei LIU Qing Xiang GUO 《中国化学快报》2006,17(5):595-598
The preparation of α-arylalkanoic acid esters has received significant attention, not only due to these compounds are important industrial materials, but also some of them are nonsteroidal anti-inflammatory drugs (NSAID)1. Arylation of β-dicarbonyl carb… 相似文献
9.
Summary A method was developed for the preparation of-keto alcohols and hence 2,3-dihydrofurans by the catalytic hydrogenation of 2-furanpropanols over platinized charcoal at 220° with formation of acetic esters of-keto alcohols, from which as a result of methanolysis-keto alcohols and dialkyldihydrofurans are formed. 相似文献
10.
Abstract The α, β-butenolide ring system is found in a number of physiologically important natural products2 and there has been recent interest in the development of methods of synthesis of compounds of this type.3 It is well known that α, β-unsubstituted butenolides may be prepared by catalytic hydrogenation of γ-hydroxy acetylenic acids.4,5b Recently, an excellent route of γ-hydroxy acetylenic esters which involves the addition of the lithium acetylide salts of propiolic esters to aldehydes5 and ketones6 has become available. We have carried out the addition of ethyl lithiopropiolate (1) to cyclohexanone (2) and 4-t-butylcyclohexanone (3) and wish to report the conversion of these adducts into corresponding β-methyl or β-methyl-α-allyl-α, β-butenolides. 相似文献
11.
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
12.
Regioselective reaction of lithium diene-and triene-diolates 1 and 2 with O-diphenylphosphinyl hydroxylamine affords unsaturated α-amino acids 3 and 4. Addition to DEAD leads selectively to γ-hydrazino unsaturated acids 5 and 6. 相似文献
13.
A new cyanide-bridged bimetallic assembly [Mn(3-meosalpn)(H2O)]2[Fe(CN)5NO](1) was obtained by the reaction of [Fe(CN)5NO]2-with [Mn(3-meosalpn)]+,and characterized by elemental analysis,IR and single-crystal X-ray structure analysis.The complex crystallizes in the monoclinic system,space group P21/c with a = 12.992(5),b = 13.274(6),c = 14.644(6) ,β = 115.198(4)o,V = 2285.2(16)3,Z = 2,C43H44FeMn2N10O11,Mr = 1042.61,Dc = 1.515 g/cm3,F(000) = 1072,μ = 0.928 mm-1,S = 1.052,the final R = 0.0347 and wR = 0.0957 for 17377 observed reflections(Ⅰ 2σ(Ⅰ)).X-ray single-crystal diffraction analysis reveals that 1 has a trinuclear molecular structure,in which the two [Mn(3-meosalpn)(H2O)]+ cations are linked by the central [Fe(CN)5NO]2-anion via two trans CN-groups.Furthermore,the two [Mn(3-meo-salpn)(H2O)]+ cations and [Fe(CN)5NO]2-anion are connected into a one-dimensional zigzag chain through hydrogen bonding interactions. 相似文献
14.
A synthesis of β-stannyl esters from ester enolates and iodomethyl (tri-n-butyl) stannane (3) is described. 相似文献
15.
Becauseoftheimportanceofbenzothiazepinederivatives,whichexhibitversatilebiologicalactivities.thechemistryofbenzothiazepinehasarousedinterestforalongtime'-'.Inourpreviouspapers.wehavereportedthesynthesisandelucidationofthestereostructureoftwokindsofl,5-benzothiazepine-6-lactams'-'.InordertoelucidatetheinfluenceofthesizeofthesubstituentatC-2ontheconfigurationof0-lactammoietyandfurtherstudythestereochemistryofthecycloadditionreaction.wepreparedaseriesofnewfi-lactamderivativesofI.5-benzothiazepine… 相似文献
16.
Dikusar E. A. Kozlov N. G. Popova L. A. Moiseichuk K. L. Yuvchenko A. P. 《Russian Journal of General Chemistry》2003,73(4):591-595
A series of peroxy-containing tertiary alcohols were prepared by the reactions of lithium peroxy acetylenides with -amino ketones. The reactions of the intermediate lithium peroxy alcoholates with alkyl iodides in the presence of hexamethylphosphoramide yielded the corresponding peroxy ethers. The thermal stability of the compounds synthesized was evaluated by thermal analysis. 相似文献
17.
A novel and efficient method for the synthesis of mercaptothiophenes using cyanodithioic acids and their corresponding mono‐ and dithiolate salts as starting components is described. 相似文献
18.
Dialdehyde in Heterocyclic Synthesis: Synthesis of Compounds Containing Two 4H-Benzopyran Building Blocks under Microwave Irradiation 总被引:2,自引:0,他引:2
The syntheses of 4H-benzopyran derivatives were investigated using dialdehyde as a key starting material. The reaction proceeds under microwave irradiation in good yield (87%--95%) with short reaction time (5--8 min),therefore providing a rapid and efficient method of synthesizing a variety of compounds containing two 4H-benzopyran units. 相似文献
19.
Sharutin V. V. Sharutina O. K. Zadachina O. P. Litvinova S. A. Reutov V. A. Gerasimenko A. V. Gerasimenko E. A. Bukvetskii B. V. Popov D. Yu. 《Russian Journal of Coordination Chemistry》2003,29(1):6-10
Tetraphenylantimony -ethylacetylacetonate and -allylacetylacetonate were synthesized by reacting pentaphenylantimony with -ethylacetylacetone or -allylacetylacetone in toluene. Their structures were determined by X-ray diffraction analysis. The coordination polyhedron of the antimony atom is a distorted octahedron. In the tetraphenylantimony -ethylacetylacetonate, the Sb–C bond lengths vary in the 2.156(2)–2.170(1) Å range, the SbOC(1)C(2)C(1")O" heterocycle is symmetric, and the Sb–O and O–C distances are 2.201(1) and 1.284(2) Å, respectively. In the tetraphenylantimony -allylacetylacetonate, the Sb–C bond lengths vary in the 2.159(1)–2.167(1) Å range and the Sb–O(1,2) distances are 2.234(1) and 2.191(1) Å. 相似文献
20.
V. F. Rudchenko I. I. Chervin A. É. Aliev R. G. Kostyanovskii 《Russian Chemical Bulletin》1991,40(7):1380-1386
The -nitrosoalcohols (II), (XII), and (IX), respectively, have been synthesized by acid-catalyzed hydrolysis of 2-alkoxyisoxazolidines (I), (Xa, b), (Xla, b), and 3-(dimethoxyamino)-3-trifluoromethylbutanol-1 (VIII). The nitrosoalcohol (II) readily rearranges into the oxime (III), and (XII) is converted into the diol (XIII) by oxidation with atmospheric O2 and denitrosation. For (IX) and (XII) ring-chain tautomerism with formation of 2-hydroxyisoxazolidines could not be detected by PMR spectroscopy.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1563–1568, July, 1991. 相似文献