99520-55-5Relevant academic research and scientific papers
Catalytic studies of cyclometalated gold(III) complexes and their related UiO-67 MOF
?ien-?degaard, Sigurd,Fiksdahl, Anne,Kaur, Gurpreet,Levchenko, Volodymyr A.,Siah, Huey-San Melanie,Tilset, Mats
, (2020/06/01)
Cyclometalated gold(III) complexes Au(L)(OAcF)2 (L = phenylpyridine dicarboxylic diester (ppyde) or phenylpyridine dicarboxylic acid (ppydc)) have been prepared reacting Au(OAc)3 with corresponding phenyl pyridines (ppyde or ppydc) in trifluoroacetic acid (HOAcF) under microwave heating. Further treatment of Au(L)(OAcF)2 with aqua regia resulted in dichloro complexes Au(L)Cl2. Au-functionalized UiO-67 MOF has been synthesized by exchanging linkers of UiO-67 with Au(ppydc)Cl2, furnishing the MOF with (N^C)-cyclometalated Au(III) centers. The catalytic activities of the molecular cyclometalated complexes and the Au-incorporated MOF were studied in gold-catalyzed propargyl ester cyclopropanations. Almost all complexes and the MOF showed catalytic activity to the cyclopropanation product (up to 97% conversion), with a preference for the trans diastereoisomer (up to 14:86 d.r.). The recyclability of the most active molecular complex has also been investigated.
Palladium- and Rhodium-Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes Towards Chiral Pyrazoles
Hilpert, Lukas J.,Sieger, Simon V.,Haydl, Alexander M.,Breit, Bernhard
supporting information, p. 3378 - 3381 (2019/02/06)
A complementing Pd- and Rh-catalyzed dynamic kinetic resolution (DKR) of racemic allenes leading to N-allylated pyrazoles is described. Such compounds are of enormous interest in medicinal chemistry as certified drugs and potential drug candidates. The new methods feature high chemo-, regio- and enantioselectivities aside from displaying a broad substrate scope and functional group compatibility. A mechanistic rational accounting for allene racemization and trans-alkene selectivity is discussed.
Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition
Pradhan, Tapas R.,Mohapatra, Debendra K.
, p. 3605 - 3611 (2019/07/04)
A metal-free oxyacetoxylation method of primary, secondary and tertiary propargylic carboxylates with retention of chirality was presented. The reaction proceeds through the intramolecular nucleophilic attack of the neighboring carbonyl group on an alkynyliodonium intermediate. The process is general with broad substrate scope and is amenable for application to a variety of propargyl carboxylates including those obtained from natural products. Insight into the mechanistic pathway by isotopic labelling (using H2O18 and D2O) and controlled experiments confirmed. (Figure presented.).
Trialkylborane-Mediated Multicomponent Reaction for the Diastereoselective Synthesis of Anti-δ,δ-Disubstituted Homoallylic Alcohols
Horino, Yoshikazu,Murakami, Miki,Aimono, Ataru,Lee, Jun Hee,Abe, Hitoshi
, p. 476 - 480 (2019/01/14)
The trialkylborane/O2-mediated reaction of propargyl acetates having a tributylstannyl group at an alkyne terminus with aldehydes in a THF-H2O solvent system gave anti-δ,δ-disubstituted homoallylic alcohols with good to high diastereoselectivity. Intriguingly, two alkyl groups derived from trialkylborane were embedded into the reaction product. The trialkylborane plays a key role not only as a radical initiator but also as a source of alkyl radicals.
Trialkylborane-Mediated Propargylation of Aldehydes Using γ-Stannylated Propargyl Acetates
Horino, Yoshikazu,Murakami, Miki,Ishibashi, Mayo,Lee, Jun Hee,Watanabe, Airi,Matsumoto, Rio,Abe, Hitoshi
, p. 9564 - 9568 (2019/12/24)
A transition-metal-free three-component process that combines aldehydes, 3-(tributylstannyl)propargyl acetates formed in situ from readily available propargyl acetates, and trialkylboranes provides access to a range of 1,2,4-trisubstituted homopropargylic alcohols. The addition of diisopropylamine plays a crucial role in the selective formation of homopropargylic alcohols. Importantly, this methodology can be extended to a single-flask reaction sequence starting from propargyl acetates.
Cu-Pybox catalyzed synthesis of 2,3-disubstituted imidazo[1,2-a]pyridines from 2-aminopyridines and propargyl alcohol derivatives
Cheng, Cang,Ge, Luo,Lu, Xuehe,Huang, Jianping,Huang, Haocheng,Chen, Jie,Cao, Weiguo,Wu, Xiaoyu
, p. 6866 - 6874 (2016/10/04)
A highly efficient cascade sequence for syntheses of 2,3-disubstituted imidazo[1,2-a]pyridines with exclusive regioselectivity in moderate to excellent yields has been developed. This cascade was initiated through propargylation of 2-aminopyridines at pyridine-nitrogen with propargyl alcohol derivatives using Cu(II)-Pybox as catalyst and followed by an intramolecular cyclization and isomerization. Besides 2-aminopyridine, less reactive 2-aminopyrimidine, 2-aminopyrazine and 3-aminopyridazine were also suitable in this cascade.
Diastereo- and enantioselective propargylation of benzofuranones catalyzed by pybox-copper complex
Zhao, Long,Huang, Guanxin,Guo, Beibei,Xu, Lijun,Chen, Jie,Cao, Weiguo,Zhao, Gang,Wu, Xiaoyu
, p. 5584 - 5587 (2015/02/19)
Diastereo- and enantioselective preparation of 2,2-disubstituted benzofuran-3(2H)-one has been realized by a pybox-copper catalyzed reaction between 2-substituted benzofuran-3(2H)-one and propargyl acetate. The utility of this method was demonstrated by further transformation of the terminal alkyne into a methyl ketone without loss of enantiomeric purity.
Stereocontrol in palladium-catalyzed propargylic substitutions: Kinetic resolution to give enantioenriched 1,5-enynes and propargyl acetates
Ardolino, Michael J.,Eno, Meredith S.,Morken, James P.
supporting information, p. 3413 - 3419 (2013/12/04)
Kinetic resolution during the catalytic allyl-propargyl cross-coupling with chiral starting materials can be accomplished with a chiral palladium catalyst. These reactions offer ready access to enantiomerically enriched enyne products from simple, readily
Construction of 1,5-enynes by stereospecific Pd-catalyzed allyl-propargyl cross-couplings
Ardolino, Michael J.,Morken, James P.
, p. 8770 - 8773 (2012/07/02)
The palladium-catalyzed cross-coupling of chiral propargyl acetates and allyl boronates delivers chiral 1,5-enynes with excellent levels of chirality transfer and can be applied across a broad range of substrates.
Enantioselective copper-catalysed propargylic substitution: Synthetic scope study and application in formal total syntheses of (+)-anisomycin and (-)-cytoxazone
Detz, Remko J.,Abiri, Zohar,Le Griel, Remi,Hiemstra, Henk,Van Maarseveen, Jan H.
, p. 5921 - 5930 (2011/06/26)
A copper catalyst with a chiral pyridine-2,6-bisoxazoline (pybox) ligand was used to convert a variety of propargylic esters with different side chains (R=Ar, Bn, alkyl) into their amine counterparts in very high yields and with good enantioselectivities (up to 90% enantiomeric excess (ee)). Different amine nucleophiles were applied in the reactions and the highest enantioselectivities were obtained for aniline and its analogues. Interestingly, some carbon nucleophiles could also be used and with indoles excellent ee values were obtained (up to 98% ee). The versatility of the propargylic amines obtained was demonstrated by their further elaboration to formal total syntheses of the antibiotic (+)-anisomycin and the cytokine modulator (-)-cytoxazone. Copyright
