704-99-4Relevant academic research and scientific papers
Domino Aryne Annulation via a Nucleophilic-Ene Process
Xu, Hai,He, Jia,Shi, Jiarong,Tan, Liang,Qiu, Dachuan,Luo, Xiaohua,Li, Yang
supporting information, p. 3555 - 3559 (2018/03/21)
1,2-Benzdiyne equivalents possess the unique property that they can react with two arynophiles through iteratively generated 1,2- and 2,3-aryne intermediates. Upon rational modification on the second leaving group of these aryne precursors, a domino aryne annulation approach was developed through a nucleophilic-ene reaction sequence. Various benzo-fused N-heterocyclic frameworks were achievable under transition metal-free conditions with a broad substrate scope.
Direct palladium-catalyzed allylic alkylations of alcohols with enamines: Synthesis of homoallyl ketones
Bouhalleb, Ghalia,Mhasni, Olfa,Poli, Giovanni,Rezgui, Farhat
supporting information, p. 2525 - 2529 (2017/06/13)
An efficient, direct nucleophilic allylic substitution of α-, β- and γ-substituted alcohols with enamines, using the Pd(OAc)2/PPh3 catalyst system and ZnBr2 as a promoter in CH2Cl2 at reflux, is reported. The reaction course was dependent on the steric hindrance at the α- or γ-positions with respect to the functionalized α-carbon, selectively affording in moderate to good yields, α- or γ-homoallyl ketones, the so-called “linear” and “branched” products, respectively.
Palladium-catalyzed allylic alkylation of simple ketones with allylic alcohols and its mechanistic study
Huo, Xiaohong,Yang, Guoqiang,Liu, Delong,Liu, Yangang,Gridnev, Ilya D.,Zhang, Wanbin
supporting information, p. 6776 - 6780 (2014/07/08)
Allylic alcohols were directly used in Pd-catalyzed allylic alkylations of simple ketones under mild reaction conditions. The reaction proceeded smoothly at 20°C by the concerted action of a Pd catalyst, a pyrrolidine co-catalyst, and a hydrogen-bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the π-allylpalladium complex by lowering the activation barrier. Concerted action: Allylic alcohols were directly used in the title reaction under mild conditions. The reaction smoothly proceeds by the concerted action of a Pd catalyst, a pyrrolidine co-catalyst, and a hydrogen-bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the π-allylpalladium complex by lowering the activation barrier.
Manganese(III)-promoted tandem oxidation and cyclization of β-keto ester derivatives of terpenoids
Li, Zhilong,Jung, Heejung,Park, Mira,Lah, Myoung Soo,Koo, Sangho
supporting information; experimental part, p. 1913 - 1917 (2011/10/08)
A new type of terpenoid cyclization directed by a β-keto ester moiety has been developed, which proceeded by manganese(III)-initiated oxidation of the β-keto ester, followed by an intramolecular hetero Diels-Alder reaction with the terpenoid chain. This reaction produces polycyclic dihydropyrans in high yields and stereoselectivities under mild conditions. Copyright
Trialkylsilyl triflimides as easily tunable organocatalysts for allylation and benzylation of silyl carbon nucleophiles with non-genotoxic reagents
Mendoza, Oscar,Rossey, Guy,Ghosez, Léon
supporting information; experimental part, p. 2571 - 2575 (2010/06/21)
Trialkylsilyl triflimides generated in situ are unique catalysts for the electrophilic benzylation or allylation of trialkylsilylenol ethers or allyl trialkylsilanes with non-genotoxic alkylating reagents such as benzyl and allyl acetates. In most cases the reactions are fast at room temperature and yields are high. The reaction works particularly well with electron-rich benzyl donors including derivatives of pyrrole, indole and furane.
Mechanistic dichotomy in CpRu(CH3CN)3PF6 catalyzed enyne cycloisomerizations
Trost, Barry M.,Toste, F. Dean
, p. 5025 - 5036 (2007/10/03)
Enynes are easily accessible building blocks as a result of the rich chemistry of alkynes and thus represent attractive substrates for ring formation, A ruthenium catalyst for cycloisomerization effects such reaction of 1,6- and 1,7-enynes typically at room temperature in acetone or DMF under neutral conditions. The reaction is effective for forming five- and six-membered rings of widely divergent structure. The alkyne may bear both election-donating and election-withdrawing substituents. The alkene may be di- or trisubstituted. Introduction of a quaternary center at the propargylic position of an ynoate, however, completely changes the nature of the reaction. In the case of a 1,6-enynoate, a seven-membered ring forms in excellent yield under equally mild conditions. Evidence is presented to indicate a complete change in mechanism. In the former case, the reaction involves the intermediacy of a ruthenacyclopentene. In the latter case, a C-H insertion to form a π-allylruthenium intermediate is proposed and supported by deuterium-labeling studies. A rationale is presented for the structural dependence of the mechanism.
Halonium ion-mediated reaction of unsaturated hydroperoxy acetals. Competition between the formation of cyclic peroxides and the migration of the methoxy (or hydroxy) group
Tokuyasu, Takahiro,Masuyama, Araki,Nojima, Masatomo,McCullough, Kevin J.
, p. 1069 - 1075 (2007/10/03)
Monoozonolyses of dienes 2 in methanol gave in each case the corresponding unsaturated α-methoxy hydroperoxides 3. Capture of 2-alkyl- substituted cyclohexanone oxides by methanol was highly diastereoselective, thereby providing exclusively the hydroperoxides derived from attack by methanol from the less hindered face of the carbonyl oxide intermediates. Halonium ion-mediated reactions of the hydroperoxides 3 gave the novel methoxy- or hydroxy-migrated products, together with the expected halogen- substituted 1,2-dioxanes and/or 1,2-dioxepanes, the composition of the product mixture being a function of the halogenating agent utilized and the structure of 3.
Allylation with substituted vinylthionium ions from SnCl4 ionisation of 1,3- and 3,3-bis(alkyl/phenylthio)propenes
Hunter,Michael,Walter
, p. 9377 - 9398 (2007/10/02)
α- and γ-substituted vinylthionium ions from SnCl4 ionisation of a range of substituted 1,3- and 3,3-bis(alkyl/phenylthio)propenes allylate enol silyl ethers in good yield. Levels of regioselectivity are sterically dependent and in the case of
Convenient Radical α-Monoallylations of Carbonyl Compounds
Watanabe, Yoshihiko,Yoneda, Tetsuo,Okumura, Tatsuya,Ueno, Yoshio,Toru, Takeshi
, p. 3030 - 3033 (2007/10/02)
Free radical allylations of α-seleno carbonyl compounds with tributyl-substituted 2,4-pentadienyltin, 2-methyl-2-propenyltin, 2-butenyltin, and 3-methyl-2-butenyltin, are described. Such successful C-C bond formations, in particular with the 2-butenyltin and the 3-methyl-2-butenyltin, are owing to the high reactivity of the α-carbon radical, generated from α-seleno carbonyl compounds, toward allylic tin compounds.
SYNTHESIS OF STABLE ANALOGUES OF TXA2
Evans, Elizabeth H.,Hewson, Alan T.,March, Lorraine A.,Nowell, Ian W.,Wadsworth, Alan H.
, p. 137 - 150 (2007/10/02)
Intramolecular aldol condensations and intramolecular Lewis acid-catalysed alkylations are used in approaches to substituted bicyclononanes and bicyclooctanes, specifically the oxo esters ( 7 ), ( 8 ), and ( 9 ).A ring expansion to a cycloheptane derivative is observed on treatment of the cyclopentyl derivative ( 18 ) with acid, and the bicyclodecane and bicyclononane derivatives ( 34 ) and ( 36 ) are obtained from the prenyl derivatives ( 30 ) and ( 35 ) respectively.The oxo esters ( 7 ), (8 ), and ( 9 ) are converted into the stable TXA2 analogues ( 10 ), ( 11 ), and ( 12 ) respectively, by a series of reactions which involve stereospecific functionalisation of their ketone and ester groups.
