3923-52-2Relevant academic research and scientific papers
Syntheses and characterizations of Zn (Ⅱ) Phthalocyanines & Naphthopyrans based polymers for improved nonlinear optical properties
Dong, Wenyue,Duan, Qian,Gao, Bo,Liu, Dajun,Wang, Jihua
, (2020)
In this paper, four organic polymers of poly [(MMA)x-co-(NPMA)y-co-(CPMA)z] and four zinc phthalocyanine (ZnPc) polymers of poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] have been successfully synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, where MMA is methyl methacrylate, NPMA is 3,3-diphenyl-8-methacryloxy-3H-naphtho [2,1-b]pyran, and CPMA is 3,4-dicyanophenyl methacrylate. The components of these polymers have been fully characterized by 1H and 13C NMR, FT-IR, Raman, XPS, UV–Vis, and photoluminescence (PL) spectroscopy. From PL spectra, poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] polymers display strong fluorescence quenching by the energy transfer (ET) process between NPMA and ZnPc moieties. The third-order nonlinear optical (NLO) properties of poly [(MMA)x-co-(NPMA)y-co-(ZnPc)z] polymers have been investigated by the Z-scan technique, and poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2] (Q4) showed the best NLO properties owing to the much stronger ET between NP and ZnPc units. Furthermore, it is essential to obtain doped poly (methyl methacrylate) (PMMA) films for practical application. The poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2]/PMMA film exhibited a higher nonlinear absorption coefficient of 61 × 10?11 m/W and a lower limiting threshold of 0.19 J/cm2. The significantly enhanced NLO properties of poly [(MMA)168-co-(NPMA)5.2-co-(ZnPc)1.2]/PMMA film compared with solution are attributed to the weaker aggregation effect in PMMA film. This research provides a promising molecular design strategy for high performance NLO materials.
Preparation of anthranilsviachemoselective oxidative radical cyclization of 3-(2-azidoaryl) substituted propargyl alcohols
Gao, Chao,Xu, Jian,Zhu, Shuxian,Jian, Kaixia,Xuan, Qingqing,Song, Qiuling
, p. 2037 - 2040 (2021)
In the presence of K2S2O8and HOAc, 3-(2-azidoaryl) substituted propargyl alcohols can go through chemoselective oxidative radical cyclizations to give a pool of anthranils based on Meyer-Schuster rearrangement. It's proposed that the cyclizations were triggered exclusively by the direct attack of oxygen radicals on the azides. The weak N-O bonds in anthranils could be easily cleaved in the presence of transition metal catalysts and went through aminations with 2-oxo-2-phenylacetic acid and iodobenzene.
Fluorocyclization of Allyl Alcohols and Amines to Access 3-Functionalized Oxetanes and Azetidines
Cao, Shanshan,Li, Linxuan,Liu, Zhaohong,Ning, Yongquan,Wu, Yong,Zanoni, Giuseppe,Zhang, Qi,Zhang, Xinyu
supporting information, p. 3674 - 3679 (2021/05/31)
An efficient method to prepare 3-functionalized oxetanes and azetidines has been realized by fluorocyclization of readily available 2-azidoallyl/2-alkoxyallyl alcohols and amines. Notably, this is the first example applying the fluorocyclization strategy to construct four-membered heterocycles. The pendant electron-donating group (-N3 or -OR) plays a crucial role in polarizing the C= C double bond and facilitating the cyclization process, as verified by DFT and experimental studies.
Development of Axially Chiral Styrene-Type Carboxylic Acid Ligands via Palladium-Catalyzed Asymmetric C-H Alkynylation
Cui, Ru,Jin, Ruo-Xing,Li, Fei,Li, Yan,Wang, Xi-Sheng,Wu, Bing-Bing,Wu, Tian-Rui,Yang, Chi
supporting information, p. 8132 - 8137 (2021/11/01)
A weakly coordinated carboxylate-directed palladium-catalyzed atroposelective C-H alkynylation method for the development of novel axially chiral styrene-type carboxylic acids is disclosed. This transformation exhibits good yields (up to 85%), excellent enantiocontrol (up to 99% ee), and mild conditions. Notably, the synthetic utility of the resulting alkynyl carboxylic acid derivatives was demonstrated by various derivatizations as well as their potential as chiral ligands in asymmetric C-H activations.
Calcium-Catalyzed Intramolecular Hydroamination-Deacylation Reaction of in situ formed β-Amino Allenes
Yaragorla, Srinivasarao,Latha, Dandugula Sneha,Rajesh, Pallava
supporting information, p. 5486 - 5492 (2021/12/10)
We have developed a simple, One-Pot, three-component reaction of tert-propargyl alcohols, primary amines and acyl ketones to synthesize fully substituted pyrroles and pyridine derivatives in good to excellent yields with large substrate diversity. An eco-friendly calcium catalyst catalyzes the reaction to form the key intermediate β-amino allene that undergoes subsequent Thorpe-Ingold effect assisted hydroamination and aromaticity driven deacylation reaction to yield fully substituted five and six-membered azacyclic compounds. (Figure presented.).
Direct Exploitation of the Ethynyl Moiety in Calcium Carbide Through Sealed Ball Milling
Hosseini, Abolfazl,Schreiner, Peter R.
, p. 4339 - 4346 (2020/07/04)
Ball milling of calcium carbide (CaC2) enables the reaction of its ethynyl moiety with organic electrophiles. This was realized simply by co-milling CaC2 with organic substrates in a sealed jar without the need for an additive or a catalyst. Various ketones including those bearing α-hydrogens were ethynylated in good yields at short reaction times. Aryl halides are also amenable substrates for this protocol as they furnish aryl ethynes through a benzyne intermediate. This method offers a practical and cheap alternative to the established procedures for introducing ethynyl functionalities.
Mechanosynthesis of Odd-Numbered Tetraaryl[n]cumulenes
Ardila-Fierro, Karen J.,Bolm, Carsten,Hernández, José G.
supporting information, p. 12945 - 12949 (2019/08/01)
A mechanochemical synthesis of one-dimensional carbon allotrope carbyne model compounds, namely tetraaryl[n]cumulenes (n=3, 5) was realized. Central for the mechanosynthesis of the cumulenic carbon nanostructures were the development of a mechanochemical Favorskii alkynylation-type reaction and the implementation of a solvent-free, acid-free reductive elimination with tin(II) chloride by ball milling.
Transition-Metal-Free Radical Hydrotrifluoromethylation of Alkynes
Matcha, Kiran,Antonchick, Andrey P.
supporting information, p. 309 - 312 (2019/01/24)
A combination of readily available and bench-stable CF3SO2Na and tBuOOH was efficiently used for hydrotrifluoromethylation of alkynes. An excellent trans-selectivity was demonstrated in the synthesis of alkenes. The developed mild reaction conditions allow the supression of the competing Meyer–Schuster-type rearrangement.
α-Hydroxy Ketones as Masked Ester Donors in Br?nsted Base Catalyzed Conjugate Additions to Nitroalkenes
Olaizola, Iurre,Campano, Teresa E.,Iriarte, Igor,Vera, Silvia,Mielgo, Antonia,García, Jesús M.,Odriozola, José M.,Oiarbide, Mikel,Palomo, Claudio
supporting information, p. 3893 - 3901 (2018/03/21)
The catalyst-controlled enantioselective direct addition reaction of enolizable esters and related carboxylic acid derivatives to π electrophiles remains a difficult synthetic transformation. In this study, the suitability of α-hydroxy ketones as ester equivalents capable of being activated by bifunctional Br?nsted base catalysts in the context of conjugate addition reactions to nitroolefins is demonstrated. The scope of the reaction, which affords the corresponding Michael adducts with very high stereoselectivity (diastereomeric ratio (d.r.) ≥95:5, up to 99 % enantiomeric excess (ee)), and its limitations are explored, as is the aftermath elaboration of adducts into densely functionalized enantioenriched products.
Synthesis, Characterization, and Reactivity of Cationic Gold Diarylallenylidene Complexes
Kim, Nana,Widenhoefer, Ross A.
supporting information, p. 4722 - 4726 (2018/03/27)
Methoxide abstraction from gold acetylide complexes of the form (L)Au[η1-C≡CC(OMe)ArAr′] (L=IPr, P(tBu)2(ortho-biphenyl); Ar/Ar′=C6H4X where X=H, Cl, Me, OMe) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) at ?78 °C resulted in the formation of the corresponding cationic gold diarylallenylidene complexes [(L)Au=C=C=CArAr′]+ OTf? in ≥85±5 % yield according to 1H NMR analysis. 13C NMR and IR spectroscopic analysis of these complexes established the arene-dependent delocalization of positive charge on both the C1 and C3 allenylidene carbon atoms. The diphenylallenylidene complex [(IPr)Au=C=C=CPh2]+ OTf? reacted with heteroatom nucleophiles at the allenylidene C1 and/or C3 carbon atom.
