91448-19-0Relevant academic research and scientific papers
Synthesis of Lactams via Ir-Catalyzed C-H Amidation Involving Ir-Nitrene Intermediates
Li, Xiaoxun,Liu, Jitian,Tang, Weiping,Wang, Shuojin,Ye, Wenjing,Zheng, Junrong
, (2020)
x-membered lactams were synthesized via either an amidation of sp3 C-H bonds or an electrophilic substitution of arenes via Ir-nitrene intermediates. With the employment of a readily available iridium catalyst in dichloromethane or hexafluoro-2-propanol, a wide range of lactams were synthesized in good to excellent yields with high selectivity.
Selective formation of γ-lactams via C-H amidation enabled by tailored iridium catalysts
Hong, Seung Youn,Park, Yoonsu,Hwang, Yeongyu,Kim, Yeong Bum,Baik, Mu-Hyun,Chang, Sukbok
, p. 1016 - 1021 (2018/03/09)
Intramolecular insertion of met al nitrenes into carbon-hydrogen bonds to form γ-lactam rings has traditionally been hindered by competing isocyanate formation. We report the application of theory and mechanism studies to optimize a class of pentamethylcyclopentadienyl iridium(III) catalysts for suppression of this competing pathway. Modulation of the stereoelectronic properties of the auxiliary bidentate ligands to be more electron-donating was suggested by density functional theory calculations to lower the C-H insertion barrier favoring the desired reaction. These catalysts transform a wide range of 1,4,2-dioxazol-5-ones, carbonylnitrene precursors easily accessible from carboxylic acids, into the corresponding γ-lactams via sp3 and sp2 C-H amidation with exceptional selectivity. The power of this method was further demonstrated by the successful late-stage functionalization of amino acid derivatives and other bioactive molecules.
Evaluation of pyrrolidin-2-imines and 1,3-thiazolidin-2-imines as inhibitors of nitric oxide synthase
Shankaran,Donnelly, Karla L.,Shah, Shrenik K.,Guthikonda, Ravindra N.,MacCoss, Malcolm,Humes, John L.,Pacholok, Stephen G.,Grant, Stephan K.,Kelly,Wong
, p. 4539 - 4544 (2007/10/03)
Syntheses and evaluation of pyrrolidin-2-imines and 1,3-thiazolidin-2- imines as inhibitors of nitric oxide synthase (NOS) are discussed. An extensive SAR was established for pyrrolidin-2-imines class of compounds. The amidines came out as the most potent inhibitors in addition to displaying selectivity.
Synthesis and Reactions of Iodo Lactams
Knapp, Spencer,Levorse, Anthony T.
, p. 4006 - 4014 (2007/10/02)
The synthesis of a series of iodo lactams has been achieved by a new cyclization method that depends on generating N,O-bis(trimethylsilyl)imidate derivatives as intermediates.Treatment of an unsaturated amide with trimethylsilyl triflate in pentane and then iodine in tetrahydrofuran gives the iodo lactam.Some reactions of this new difunctional group with bases, nucleophiles, and Michael acceptors leading to functionalized or elaborated lactams are presented.In general, iodo lactams undergo direct SN2 reactions with reactive (but weakly basic) nucleophiles like azide and triphenylphosphine and elimination or decomposition in the presence of bases or basic nucleophiles.Sodium hydride may be used to generate an N-acylaziridine intermediate, which can be opened with azide to deliver an azido lactam with overall retention of stereochemistry.Silver-assisted solvolysis of iodo lactams gives the hydroxy lactams with retention of configuration, probably also because of participation by the lactam nitrogen.The sodium salt of 5-(iodomethyl)-2-pyrrolidinone (3), generated at -20 deg C, undergoes an annulation reaction with unsaturated esters (but not sulfones), leading to pyrrolizidine derivatives.
