نتایج جستجو برای: intramolecular cyclization
تعداد نتایج: 18338 فیلتر نتایج به سال:
The intramolecular asymmetric cyclization of aldehydes has been accomplished using singly occupied molecular orbital (SOMO) catalysis. Selective oxidation of chiral enamines (formed by the condensation of an aldehyde and a secondary amine catalyst) leads to the formation of a 3π-electron radical species. These chiral SOMO-activated radical cations undergo enantioselective cyclization with an ar...
A facile synthesis of 2-amino-1,3-oxazoles via CuI -catalyzed oxidative cyclization of enamines and N,N-dialkyl formamides has been developed. The reaction proceeds through an oxidative C-N bond formation, followed by an intramolecular C(sp2 )-H bond functionalization/C-O cyclization in one pot. This protocol provides direct access to useful 2-amino-1,3-oxazoles and features protecting-group-fr...
The weak intramolecular F∙∙∙N and S∙∙∙N interactions in the novel pyridine-containing perfluorodiarylethenes achieved high cyclization quantum yields in solutions. While the F∙∙∙N interactions stabilize the photoreactive conformation, the S∙∙∙N contacts contribute from the energetic aspect.
Activation of imide carbonyl group with trifluoromethanesulfonic acid facilitates the intramolecular cyclization of phenethylphthalimides to give a fused isoindoloisoquinolinone skeleton. The first one pot regioselective synthesis of isoindoloisoquinolinone alkaloid (±)-nuevamine has been successfully executed using this methodology.
Intramolecular nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole esters is described. Efficient routes towards the synthesis of pyrrolopyrazinone, pyrrolotriazinone and pyrrolooxazinone have been developed. First, N-alkyne-substituted pyrrole ester derivatives were synthesized. Introduction of various substituents into the alkyne functionality was accomplished by a copp...
The effective formation of 1-azabicyclo[1.1.0]butane (2) by treatment of 2,3-dibromopropylamine hydrobromide (1) with n-BuLi could be understood considering a rational reaction pathway via both transition states 10 and 19 based on the intramolecular Br...Li(+) coordination. A similar cyclization pathway starting from N-benzyl-3-bromopropylamine hydrochloride (17) to afford N-benzylazetidine (18...
A simple and efficient protocol for the construction of substituted piperazines, piperidines, thiomorpholines, decahydroquinolines, perhydrocyclopenta[b]pyridine, and pyrrolidines bearing N-hydroxy substituents through intramolecular reductive cyclization of diketoximes using sodium cyanoborohydride is described.
Novel azepino[3,4-b]indol-1-ones were synthesized from alkyne-substituted indole-2-carboxamides by catalytic intramolecular cyclization in the presence of PtCl(2). The scope and limitations of this straightforward protocol are reported.
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