154884-63-6Relevant academic research and scientific papers
NHC-catalyzed enantioselective C2-functionalization of 3-hydroxychromenonesviaα,β-unsaturated acyl azoliums
Dzieszkowski, Krzysztof,S?otwiński, Micha?,Rafińska, Katarzyna,Muzio?, Tadeusz M.,Rafiński, Zbigniew
supporting information, p. 9999 - 10002 (2021/10/06)
A novel synthetic method for enantioselective C2-functionalization of 3-hydroxychromenones promoted by N-heterocyclic carbenesviathe formation of α,β-unsaturated acyl azolium intermediates, which occurs with Coates-Claisen rearrangement is established. This synthetic strategy enabled the rapid assembly of enantiomerically enriched δ-hydroxychromenone-derived esters/amides under mild conditions with good to excellent yields and broad substrate scope.
Rhodium-Catalyzed 1,1-Hydroacylation of Thioacyl Carbenes with Alkynyl Aldehydes and Subsequent Cyclization
Zhou, Bingnan,Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3594 - 3599 (2019/05/24)
A rhodium-catalyzed 1,1-hydroacylation of thioacyl carbenes with alkynyl and alkenyl aldehydes and subsequent 6-endo-trig/dig cyclization are realized, giving structurally diverse 4H-thiopyran-4-ones and 2,3-dihydro-4H-thiopyran-4-ones in moderate to good yields. The oxidative addition of Rh(I) to aldehydes is proposed to be the turnover-limiting step. Manipulations of estrones demonstrate the applications of our formal (3 + 3) transannulations in the structural modifications of natural products.
N-heterocyclic carbene-catalyzed annulation of α-cyano-1,4-diketones with ynals
Romanov-Michailidis, Fedor,Besnard, Celine,Alexakis, Alexandre
supporting information, p. 4906 - 4909,4 (2012/12/12)
In this paper, the first stereoselective annulation reaction between r-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61-90% isolated yields and with up to 20:1 diastereomeric preference.
N-heterocyclic carbene-catalyzed annulation of α-cyano-1,4-diketones with ynals
Romanov-Michailidis, Fedor,Besnard, Céline,Alexakis, Alexandre
supporting information, p. 4906 - 4909 (2013/01/15)
In this paper, the first stereoselective annulation reaction between r-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61-90% isolated yields and with up to 20:1 diastereomeric preference.
A New Preparative Route to Substituted Dibenzofurans by Benzannulation Reaction. An Application to the Synthesis of Cannabifuran
Serra, Stefano,Fuganti, Claudio
, p. 2005 - 2008 (2007/10/03)
A new regioselective pathway to substituted dibenzofuran derivatives is described here. According to this procedure substituted 1-acetoxy-3- alkoxycarbonyl dibenzofurans are obtained by treatment of 6-(2-methoxyaryl)-3- alkoxycarbonylhex-3-en-5-ynoic acids with acetic anhydride in the presence of sodium acetate. The latter acids are prepared from the easily available substituted o-iodo-anisoles by Sonogashira coupling with propargylic alcohol and Wittig reaction as the key steps. The described benzannulation reaction proceeds in regioselective fashion and a range of substituents are tolerated. Its synthetic utility is demonstrated by a new synthesis of cannabifuran, a naturally occurring dibenzofuran.
Unexpected Course of the Reaction of 1,3-Bis(dimethylamino)trimethinium Perchlorate with 3-Substituted Prop-2-ynals Leading to 1-Aryl-2,4,6-triformylbenzenes
Suchy, Petr,Dvorak, Dalimil,Havelkova, Martina
, p. 119 - 129 (2007/10/03)
Reaction of 1,3-bis(dimethylamino)trimethinium perchlorate (1) with 3-substituted prop-2-ynals (4) in acetic anhydride at the presence of ZnBr2 gives upon hydrolysis 1-substituted 2,4,6-triformylbenzenes (6) in low to moderate yield. This reaction is restricted to prop-2-ynals bearing electron rich aromatic substituents at the 3-position.
