- Sustainable Passerini-tetrazole three component reaction (PT-3CR): selective synthesis of oxaborol-tetrazoles
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A sustainable catalyst- and solvent-free Passerini-tetrazole three component reaction (PT-3CR) has been developed for the selective synthesis of benzoxaborol-tetrazoles for the first time. The synthetic potential of oxaboroles was demonstrated towards various functionalized tetrazoles, which are otherwise difficult to achieve through conventional PT-3CR from aromatic aldehydes/ketones. The reaction features high practicality, broad substrate scope and excellent yields (80-98%). Preliminary results of the asymmetric PT-3CR are also shown for the synthesis of chiral benzoxaboroles.
- Singh, Akansha,Kumar, Ravindra
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supporting information
p. 9708 - 9711
(2021/09/30)
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- Oxacycle-Fused [1]Benzothieno[3,2-b][1]benzothiophene Derivatives: Synthesis, Electronic Structure, Electrochemical Properties, Ionisation Potential, and Crystal Structure
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The molecular properties of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) are vulnerable to structural modifications, which in turn are determined by the functionalization of the backbone. Hence versatile synthetic strategies are needed to discover the properties of this molecule. To address this, we have attempted heteroatom (oxygen) functionalization of BTBT by a concise and easily scalable synthesis. Fourfold hydroxy-substituted BTBT is the key intermediate, from which the compounds 2,3,7,8-bis(ethylenedioxy)-[1]benzothieno[3,2-b][1]benzothiophene and 2,3,7,8-bis(methylenedioxy)-[1]benzothieno[3,2-b][1]benzothiophene are synthesized. The difference in ether functionalities on the BTBT scaffold influences the ionisation potential values substantially. The crystal structure reveals the transformation of the herringbone motif in bare BTBT towards π-stacked columns in the newly synthesized derivatives. The results are further justified by the simulated HOMO levels of the model compound.
- Mohankumar, Meera,Chattopadhyay, Basab,Hadji, Rachid,Sanguinet, Lionel,Kennedy, Alan R.,Lemaur, Vincent,Cornil, Jér?me,Fenwick, Oliver,Samorì, Paolo,Geerts, Yves
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p. 1263 - 1269
(2018/11/23)
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- PROCESS FOR PRODUCTION OF OPTICALLY ACTIVE 4-HYDROXY-1,2,3,4 -TETRAHYDROQUINOLINES
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The present invention relates to a method for preparing an optically active 4-hydroxy-1,2,3,4-tetrahydroquinoline compound [I], which comprises the steps of: treating a racemic 4-hydroxy-1,2,3,4-tetrahydroquinoline compound represented by general formula [I]: [wherein R 1 represents a hydrogen atom or a protecting group for amino group.] with an enzyme having an ability of selectively or preferentially acylating one enantiomer of the racemic compound [I] in the presence of an acyl donor; and if necessary, subjecting the reaction product to solvolysis.
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- Fused Catechol Ethers from Gold(I)-Catalyzed Intramolecular Reaction of Propargyl Ethers with Acetals
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Selective gold(I)-catalyzed rearrangement of aromatic methoxypropynyl acetals leads to fused catechol ethers (1,2-dialkoxynapthalenes) in excellent yields. Furthermore, this process extends to the analogous heterocyclic and aliphatic substrates. Alkyne activation triggers nucleophilic addition of the acetal oxygen that leads to an equilibrating mixture of oxonium ions of similar stability. This mixture is "kinetically self-sorted" via a highly exothermic cyclization. Selective formation of 1,2-dialkoxy naphthalenes originates from chemoselective aromatization of the cyclic intermediate via 1,4-elimination of methanol.
- Pati, Kamalkishore,Dos Passos Gomes, Gabriel,Harris, Trevor,Alabugin, Igor V.
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supporting information
p. 928 - 931
(2016/03/15)
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- Enantioselective intramolecular propargylic amination using chiral copper-pybox complexes as catalysts
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Intramolecular propargylic amination of propargylic acetates bearing an amino group at the suitable position in the presence of chiral copper-pybox complexes proceeds enantioselectively to give optically active 1-ethynyl-isoindolines (up to 98% ee). The method described in this communication provides a useful synthetic approach to the enantioselective preparation of nitrogen containing heterocyclic compounds with an ethynyl group at the α-position. This journal is the Partner Organisations 2014.
- Shibata, Masashi,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 7874 - 7877
(2014/07/08)
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- OPTICALLY ACTIVE CYCLIC ALCOHOL COMPOUND AND METHOD FOR PRODUCING SAME
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Disclosed is a method for producing an optically active cyclic alcohol compound represented by the general formula [I] below, wherein a cyclic ketone compound represented by the general formula [II] below is asymmetrically reduced in the presence of (A) an optically active oxazaborolidine compound and a boron hydride compound, or alternatively in the presence of (B) an asymmetric transition metal complex obtained from a transition metal compound and an asymmetric ligand, and a hydrogen donor. Also disclosed is such an optically active cyclic alcohol compound. [I] (In the formula, the symbol is as defined below.) [II] (In the formula, R represents a hydrogen atom or a protective group of an amino group.)
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Page/Page column 26
(2010/11/26)
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- Application of the intramolecular isomerisation - Aldolisation from allylic alcohols and allylic silyl ethers to the synthesis of indanones and indenones
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A new access to indanones was discovered through a one-step nickel or iron-mediated transposition of 2-hydroxyisobenzofurans. Starting from the corresponding silylenol ethers, a new one-pot tandem isomerisation-Mukaiyama aldol process was also developed. These versatile strategies will be useful for the preparation of various types of indanones and indenones.
- Petrignet, Julien,Roisnel, Thierry,Gree, Rene
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p. 7374 - 7384
(2008/03/14)
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- Naphthalene derivatives, process for the preparation thereof, and intermediates therefor
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Naphthalene derivatives of the formula [I]: STR1 wherein R1 and R2 are the same or different and are each H, protected or unprotected OH, one of R3 and R4 is protected or unprotected hydroxymethyl, and the other is H, lower alkyl, or protected or unprotected hydroxymethyl, R5 and R6 are the same or different and are each H, substituted or unsubstituted lower alkyl, substituted or unsubstituted phenyl or protected or unprotected NH2, or both combine together with the adjacent N to form substituted or unsubstituted heterocyclic group, and pharmaceutically acceptable salts thereof, these compounds showing excellent bronchoconstriction inhibitory activity, and hence, being useful in the prophylaxis or treatment of asthma.
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- Hydroxyacetals, phtalans, and isobenzofurans therefrom
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A general method for the generation of isobenzofuran intermediates is described.Lithiated aromatic acetals are converted to hydroxyacetals (A) which may be cyclized to isobenzofurans by mild acid treatment through the 1-hydroxyphtalans (B).The isobenzofur
- Keay, Brian A.,Plaumann, Heinz P.,Rajapaksa, Dayananda,Rodrigo, Russell
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p. 1987 - 1995
(2007/10/02)
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- Potential Isobenzofurans: their Use in the Synthesis of Naturally Occurring 1-Arylnaphthalide Lignans
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A three-step synthesis of seven lignans by means of a Diels-Alder reaction followed by selective borane reduction of an aromatic ester is described.
- Plaumann, Heinz P.,Smith, James G.,Rodrigo, Russell
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p. 354 - 355
(2007/10/02)
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