4424-16-2Relevant academic research and scientific papers
Electrochemical Access to Aza-Polycyclic Aromatic Hydrocarbons: Rhoda-Electrocatalyzed Domino Alkyne Annulations
Kong, Wei-Jun,Shen, Zhigao,Finger, Lars H.,Ackermann, Lutz
, (2020)
Nitrogen-doped polycyclic aromatic hydrocarbons (aza-PAHs) have found broad applications in material sciences. Herein, a modular electrochemical synthesis of aza-PAHs was developed via a rhodium-catalyzed cascade C?H activation and alkyne annulation. A mu
Orthogonal aerobic conversion of N-benzyl amidoximes to 1,2,4-oxadiazoles or quinazolinones
Zhang, Feng-Lian,Wang, Yi-Feng,Chiba, Shunsuke
, p. 6003 - 6007 (2013/09/12)
Concise synthesis of 1,2,4-oxadiazoles was achieved by heating N-benzyl amidoximes with K3PO4 in DMF at 60°C under an O 2 atmosphere via benzylic C-H oxygenation. On the other hand, aerobic treatment of N-benzyl amidoximes
PROCESS FOR PREPARING PROTECTED AMIIDINES
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Page/Page column 13-14, (2008/06/13)
A process for preparing a protected amidine group of formula (I): wherein R6 represents, for example, C1-10 alkyl (optionally substituted), aryl, C1-3 alkylaryl or C1-3 alkyloxyaryl; which comprises reacting a n
Palladium-catalyzed N-arylation of O-methylamidoximes
Anbazhagan, Mariappan,Stephens, Chad E,Boykin, David W
, p. 4221 - 4224 (2007/10/03)
Pd-catalyzed coupling of O-methylbenzamidoximes gave N-aryl O-methylbenzamidoximes using aryl halides with electron attracting or moderate electron donating groups. Under the same conditions, benzamidoxime failed to undergo coupling and O-acetylbenzamidoxime underwent cyclization to form the corresponding [1,2,4]oxadiazole.
Heterocyclic Photorearrangements. Photochemical Behaviour of Some 3,5-Disubstituted 1,2,4-Oxadiazoles in Methanol at 254 nm
Buscemi, Silvestre,Cicero, Maria G.,Vivona, Nicolo,Caronna, Tullio
, p. 931 - 935 (2007/10/02)
Photochemical behaviour of some 3,5-disubstituted 1,2,4-oxadiazoles in methanol at 254 nm has been investigated.Ring photoisomerization to the 1,3,4-oxadiazole heterocycle or formation of open chain compounds involving the nucleophilic solvent was shown to depend on the nature and the position of the substituent.Photoinduced ring closure into the benzimidazole system, involving a 3-N-phenylamino side chain sequence and a photolytic intermediate of the oxadiazole heterocycle, is also reported.
Mechanism of the Aminolysis of Alkyl Benzimidates
Gilbert, Hiram F.,Jencks, William P.
, p. 6769 - 6779 (2007/10/02)
The aminolysis of a series of ring- and alkyl-substituted benzimidates proceeds through a mechanism involving the formation and decomposition of a tetrahedral intermediate as evidenced by a change in rate-determining step with changing pH.On the alkaline side of the pH-rate profile, formation of the tetrahedral intermediate from the free amine and protonated benzimidate is rate determining.Structure reactivity correlations for this step show a late (intermediate-like) transition state with βnuc = 0.61, β0 = -0.47 (for O-substituted benzimidates), and ρ = 1.49.There is no evidence for a kinetically significant proton-transfer step.The addition of water to alkyl benzimidates follows β0 = -0.56.On the acidic side of the pH-rate profile for aminolysis, the breakdown of the intermediate with expulsion of alcohol is the rate-determining step, as evidenced by the observation of an exchange reaction of methoxyamine for ammonia.The neutral tetrahedral intermediate (T0) partitions between acid-catalyzed expulsion of alcohol, ammonia, and methoxyamine with partition ratios of approximately 1/1/300, respectively.The expulsion of alcohol also occurs by a spontaneous (water catalyzed) reaction characterized by β0 = -1.30 and ρ = -0.01, suggesting a late (product-like) transition state for this reaction.The expulsion of alcohol through a general-acid-catalyzed reaction is characterized by relatively low Broensted α values of 0.40-0.49.The decrease in α with decreasing pK of the leaving alcohol can be described by an interaction coefficient pxy' = 1/c5 = δα/δpK1g = 0.05.This reaction can be described on a structure-reactivity diagram by a diagonal reaction coordinate that represents concerted proton transfer and C-O bond cleavage in the transition state.The effect of structure on the direction of acid-catalyzed expulsion of alcohols and amines from addition compounds is reviewed briefly.
Mechanism of Solvolysis Reactions of O-Methylbenzohydroximoyl Halides. Stereoelectronic Control in Formation of and Nucleophilic Addition to Nitrilium Ions
Johnson, James E.,Cornell, Sravanthi C.
, p. 4144 - 4148 (2007/10/02)
The hydrolysis reactions of the Z and E isomers of O-methylbenzohydroximoyl chloride (3a and 2, respectively) have been investigated. The first-order rate constant for the hydrolysis of 3a (1) shows common-ion rate depression, (2) decreases with decreasin
