145472-40-8Relevant academic research and scientific papers
Hemiaminals as substrates for sulfur ylides: Direct asymmetric syntheses of functionalised pyrrolidines and piperidines
Kokotos, Christoforos G.,Aggarwal, Varinder K.
, p. 2156 - 2158 (2006)
Phenyl stabilised chiral sulfur ylides react with five-membered-ring hemiaminals to give functionalised pyrrolidines directly with high enantioselectivity. The reaction can be diverted to give piperidines instead by isolation of the intermediate epoxide and treatment with TMSOTf. The Royal Society of Chemistry 2006.
Catalytic Ring Expansion of Cyclic Hemiaminals for the Synthesis of Medium-Ring Lactams
Zhao, Wanxiang,Qian, Hui,Li, Zigang,Sun, Jianwei
, p. 10005 - 10008 (2015)
A mild and efficient intermolecular ring-expansion approach was developed for the synthesis of medium-ring lactams by using siloxy alkynes. Key to success is the suitable combination of a superior catalyst and an exceptional nitrogen-protecting group. Control experiments indicated that the reaction is remarkably selective toward the desired lactam formation, even with many possible non-productive pathways. Growth rings: A mild catalytic synthesis of medium-ring lactams through ring expansion of cyclic hemiaminals was developed. This synthetically useful method also gives insight into the reactivity of both siloxy alkynes and N-acyliminium analogues.
One-Pot Double-Annulation Strategy for the Synthesis of Unusual Fused Bis-Heterocycles
Abdul-Rashed, Shukree,Alachouzos, Georgios,Brennessel, William W.,Frontier, Alison J.
supporting information, p. 4350 - 4354 (2020/06/04)
A novel metal-free double-annulation cascade for the construction of unusual fused heterocyclic systems is described. This simple protocol enables the sequential assembly of two rings in one pot from two simple precursors. Acidic conditions promote the condensation and the intramolecular alkynyl Prins reaction of an enyne or arenyne alcohol with a cyclic hemiaminal to form a five-, six-, or seven-membered oxacycle followed by a seven-or eight-membered azacycle. In this transformation, chemical complexity is rapidly generated with the formation of three new bonds (one C-O, one C-C, and one C-N) in one synthetic operation. The strategy is modular and relatively general, providing access to a series of unique fused bicyclic scaffolds.
Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: A computational study on the crucial role of the nitrogen atom
Zanella, Giovanna,Petrovi?, Martina,Scarpi, Dina,Occhiato, Ernesto G.,Gómez-Bengoa, Enrique
supporting information, p. 3059 - 3068 (2021/01/15)
The tandem gold(I)-catalyzed rearrangement/Nazarov reaction of enynyl acetates in which the double bond is embedded in a piperidine ring was computationally and experimentally studied. The theoretical calculations predict that the position of the propargy
Laccase/2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO): An efficient catalytic system for selective oxidations of primary hydroxy and amino groups in aqueous and biphasic media
Díaz-Rodríguez, Alba,Martínez-Montero, Lía,Lavandera, Iván,Gotor, Vicente,Gotor-Fernández, Vicente
, p. 2321 - 2329 (2014/07/21)
Copper salts/2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO) catalytic systems enable efficient aerobic oxidations of primary alcohols but they generally show a reduced reactivity in aqueous medium. Herein, we report an oxidative catalytic system composed of Trametes versicolor laccase and TEMPO, which is able to work in buffer solutions at room temperature using ambient air. Although this catalytic system displays great efficiency in aqueous systems, the addition of methyl tert-butyl ether allows the reduction of TEMPO loading, also enhancing the solubility of hydrophobic compounds. This practical methodology promotes the chemoselective aerobic oxidation of hydroxy or amino groups, leading to interesting organic derivatives such as aldehydes, lactones, hemiaminals or lactams.
Single bifunctional ruthenium catalyst for one-pot cyclization and hydration giving functionalized indoles and benzofurans
Nair, Reji N.,Lee, Paul J.,Rheingold, Arnold L.,Grotjahn, Douglas B.
supporting information; experimental part, p. 7992 - 7995 (2010/09/18)
Chemical equation Presented Bifunctional is more than twice as fun! At low loading, catalyst 1 (see scheme) can form two important heterocycle classes, apparently by attack of XH on a vinylidene intermediate. Aza- and nitroindoles can be formed, and all N-protecting groups tested (alkyl, allyl, sulfonyl) were tolerated. The newly formed ring can be deuterated in one step, and for substrates with two terminal alkynes, cyclization can be followed by hydration, making this catalyst uniquely versatile.
Carbon-Carbon Bond Formation via N-Tosyliminium Ions
Ahman, Jens,Somfai, Peter
, p. 9537 - 9544 (2007/10/02)
Addition of carbon nucleophiles to cyclic N-tosyliminium ions, derived from α-hydroxy and α-methoxy tosylamides (5a,b and 6a,b, respectively) is described.In general, good to excellent yields were obtained when allyltrimethylsilane, 1-t-butyldimethylsilyl
