Enantioselective hydrophosphonylation of N - benzyl imines, isatin derived ketimines and isatins catalyzed by in-situ generated Ti(IV) macrocyclic salen complexes
作者:Mohd Nazish、Ajay Jakhar、Noor-ul H. Khan、Shailesh Verma、Rukhsana I. Kureshy、Sayed H.R. Abdi、Hari C. Bajaj
DOI:10.1016/j.apcata.2015.12.037
日期:2016.4
benzylimines, whereas for ketiminesdiphenylphosphite (IIb) gave best results with very good yield (up to 88%) and ee (up to 99%). The Ti(IV) complex was recoverable and recyclable with retention of its catalytic performance at gram scale level. To understand the reaction mechanism NMR studies have been carried out using benzylimine as a model substrate and dimethyl phosphite as a nucleophile.
A Biphilic Phosphetane Catalyzes N–N Bond-Forming Cadogan Heterocyclization via P<sup>III</sup>/P<sup>V</sup>═O Redox Cycling
作者:Trevor V. Nykaza、Tyler S. Harrison、Avipsa Ghosh、Rachel A. Putnik、Alexander T. Radosevich
DOI:10.1021/jacs.7b03260
日期:2017.5.24
chemoselective catalytic synthesis of 2H-indazoles, 2H-benzotriazoles, and related fused heterocyclic systems with good functional group compatibility. On the basis of both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV═O cycling, where DFT modeling suggests a turnover-limiting (3+1) cheletropic addition between the phosphetane catalyst and nitroarene
An Efficient One-Pot Conversion of Alkyl Bromides Into Imines<i>Via</i>the Staudinger Reaction
作者:Petr Vaněk、Petr Klán
DOI:10.1080/00397910008087178
日期:2000.4
Abstract A new one-pot procedure for transforming primary alkyl bromides into the corresponding imines via the Staudinger reaction has been developed. Acetonitrile was found to be an excellent solvent for azidation as well as the reaction of organic azide with triphenylphosphine and a carbonyl compound.
Facile synthesis of 4-substituted 1,2,4,5-tetrahydro-1,4-benzodiazepin-3-ones by reductive cyclization of 2-chloro-N-(2-nitrobenzyl)acetamides
作者:Leandro D. Sasiambarrena、Ivan A. Barri、Guido G. Fraga、Rodolfo D. Bravo、Agustín Ponzinibbio
DOI:10.1016/j.tetlet.2018.12.029
日期:2019.1
A facile and efficient method was developed for the synthesis of 1,2,4,5-tetrahydro-1,4-benzodiazepine-3-ones from 2-chloro-N-(2-nitrobenzyl)acetamides through a reductive cyclization using iron-ammonium chloride in ethanol–water in good yields. This method provides a simple approach to these benzodiazepine-3-ones which are of high value in the field of medicinal chemistry research.
The ortho-nitro effect was discovered in sulfa-Staudinger cycloadditions of ethoxycarbonylsulfene with linear imines. When an ortho-nitro group is present at the C-aryl substituents of linear imines, the sulfa-Staudinger cycloadditions deliver cis-β-sultams in considerable amounts, together with the predominant trans-β-sultams. In other cases, the above sulfa-Staudinger cycloadditions give rise to trans-β-sultams