23092-23-1Relevant articles and documents
Gold-catalyzed [4+3]-Annulations of Benzopyriliums with Vinyldiazo Carbonyls to Form Bicyclic Heptatriene Rings with Skeletal Rearrangement
Sekar Kulandai Raj, Antony,Liu, Rai-Shung
, p. 2517 - 2522 (2020)
We report gold catalyzed [4+3]-annulations between benzopyriliums and 3-alkyl-2-diazo-3-vinyl carbonyls, yielding 7H-benzo[7]annulene products efficiently. Notably, the carbon skeletons of resulting 7H-benzo[7]annulenes are structurally rearranged, accompanied by migrations of their alkyl and ketone motifs. Apart from applicable substrates over a wide scope, these annulatios are applicable to pyriliums and 3-alkyl-2-diazo-3-vinyl esters to increase their reaction significance. We postulate a mechanism involving an initial [4+2]-cycloaddition between benzopyriliums and 3-alkyl-2-diazo-3-vinyl carbonyl species, followed by formation of gold carbenes to induce a ring expansion and group migrations. (Figure presented.).
Enantioselective Syntheses of Secondary Homoallyl Alcohols with Optically Active η3-Allylmolybdenum Complexes
Faller, J. W.,Linebarrier, D. L.
, p. 1937 - 1939 (1989)
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The application of bis(oxazoline) ligands in the catalytic enantioselective methallylation of aldehydes
Hargaden, Grainne C.,McManus, Helen A.,Cozzi, Pier Giorgio,Guiry, Patrick J.
, p. 763 - 766 (2007)
The application of symmetric and non-symmetric bis(oxazoline) ligands in the asymmetric methallylation of a range of aromatic and aliphatic aldehydes was investigated. Catalytic asymmetric methallylation of benzaldehyde was performed, using acetonitrile l
Gold-Catalyzed Bicyclic Annulations of 2-Alkynylbenzaldehydes with Vinyldiazo Carbonyls that Serve as Five-atom Building Units
Raj, Antony Sekar Kulandai,Liu, Rai-Shung
, p. 10980 - 10984 (2019)
This work reports gold-catalyzed bicyclic annulations of 2-alkynyl-1-carbonylbenzenes with vinyldiazo ketones that serve as five-atom building units. The importance of these reactions is to access 4,5-dihydro-benzo[g]indazoles, which form the structural cores of various bioactive molecules. According to our mechanistic analysis, we postulate initial [5+4]-cycloadditions between benzopyrilium intermediates and vinyldiazo ketones, followed by 6-π-electrocyclizations to achieve the excellent stereoselectivity.
Diastereoselective construction of cis 2,6-disubstituted tetrahydropyran rings via In(OTf)3-catalyzed intramolecular 2,5-oxonium-ene cyclization: Synthetic studies towards the total synthesis of zampanolide and dactylolide
Loh, Teck-Peng,Yang, Jian-Ying,Feng, Li-Chun,Zhou, Yan
, p. 7193 - 7196 (2002)
Diastereoselective construction of 2,6-disubstituted tetrahydropyrans with an exocyclic double bond was achieved via the In(OTf)3-catalyzed intramolecular 2,5-oxonium-ene cyclization. Its application was further demonstrated by the synthesis of
Accessing novel fluorinated heterocycles with the hypervalent fluoroiodane reagent by solution and mechanochemical synthesis
Browne, Duncan L.,Jones, Andrew C.,Riley, William,Singh, Kuldip,Stuart, Alison M.
supporting information, p. 7406 - 7409 (2021/08/03)
A new and efficient strategy for the rapid formation of novel fluorinated tetrahydropyridazines and dihydrooxazines has been developed by fluorocyclisation of β,γ-unsaturated hydrazones and oximes with the fluoroiodane reagent. Mechanochemical synthesis d
Highly Enantioselective Allylation Reactions of Aldehydes with Allyltrimethylsilane Catalyzed by a Chiral Oxazaborolidinium Ion
Kim, Taehyeong,Jeong, Hye-Min,Venkateswarlu, Anipireddy,Ryu, Do Hyun
supporting information, p. 5198 - 5201 (2020/07/15)
A highly enantioselective allylation reaction of aldehydes with silyl reagents was developed for the synthesis of a variety of chiral homoallylic alcohols. In the presence of a chiral oxazaborolidinium ion (COBI) catalyst, the reaction proceeded in high yield (up to 99percent) with excellent asymmetric induction (up to 99percent ee).
