1888-91-1Relevant academic research and scientific papers
Ring Expansion of Thiolactams via Imide Intermediates: An Amino Acid Insertion Strategy
Shang, Jing,Thombare, Varsha J.,Charron, Carlie L.,Wille, Uta,Hutton, Craig A.
, p. 1620 - 1625 (2020/12/23)
The AgI-promoted reaction of thiolactams with N-Boc amino acids yields an N-(α-aminoacyl) lactam that can rearrange through an acyl transfer process. Boc-deprotection results in convergence to the ring-expanded adduct, thereby facilitating an overall insertion of an amino acid into the thioamide bond to generate medium-sized heterocycles. Application to the site-specific insertion of amino acids into cyclic peptides is demonstrated.
Chemoselective palladium-catalyzed oxidation of vinyl ether to acetate using hydrogen peroxide
Kon, Yoshihiro,Tanaka, Shinji,Nakashima, Takuya,Sato, Kazuhiko,Shimada, Hiromichi
, p. 749 - 756 (2014/07/22)
A practical and environmental-friendly method was developed to convert vinyl ether into acetate by using a palladium complex with phosphine ligand and hydrogen peroxide. The only by-product is water. Chemoselective oxidation of vinyl ether and tert-enamides to form acetate and N-acetyl amide with hydrogen peroxide in the presence of palladium complex having phosphine ligand was developed under mild reaction conditions. This process is environmentally friendly because it uses hydrogen peroxide as a clean oxidant, with water being the only byprocuct.
Toward Transition Metal-Catalyzed Carbonylation of Methanol without HI as Copromoter: Catalytic Exocyclic Carbonylation of Cycloimino Esters
Xu, Hongyu,Jia, Li
, p. 3955 - 3957 (2007/10/03)
(Formula presented). Initial studies of a rare exocyclic C-O bond carbonylation are reported. Under the catalysis of Co2(CO) 8 in the absence of HI as the copromoter, cycloimino esters are carbonylated to afford N-acyllactams in high yields under relatively mild conditions (100-160°C and 200-1000 psi). The reaction is interesting because it opens up the possibility of carbonylation of alcohols in the absence of HI.
Reactions of thioamides with metal carboxylates in organic media
Avalos, Martin,Babiano, Reyes,Cintas, Pedro,Duran, Carlos J.,Higes, Francisco J.,Jimenez, Jose L.,Lopez, Ignacio,Palacios, Juan C.
, p. 14463 - 14480 (2007/10/03)
Reactions of thioamides with metal carboxylates in organic solvents are described. These processes enable the selective preparation of nitriles, imides or amides depending on the substitution pattern of the starting material. Mechanistic hypotheses supported by experimental evidences, including the unequivocal synthesis of bis(thioacetanilide)mercury(II) as a key reaction intermediate, are also proposed.
Ruthenium Tetroxide Oxidation of N-Alkyllactams
Yoshifuji, Shigeyuki,Arakawa, Yukimi,Nitta, Yoshihiro
, p. 357 - 363 (2007/10/02)
Ruthenium tetroxide (RuO4) oxidation of N-alkyllactams proceeded regioselectively depending on the size of lactam ring, except for the seven-membered ring.Four- and eight-membered N-methyl- and N-ethyllactams were oxidized at the exocyclic α-carbon adjacent to nitrogen to produce the N-acyllactams and NH-lactams, while five- and six-membered lactams underwent endocyclic oxidation to yield the cyclic imides.Oxidation of seven-membered lactams yielded a mixture of products arising from both exocyclic and endocyclic oxidations.These regioselectivities were confirmed in the oxidation of substrates having a tertiary carbon at the oxidation position.Keywords---oxidation; ruthenium tetroxide oxidation; regioselective oxidation; hydroxylation; imide synthesis; N-alkyllactam; N-acyllactams; imide; ruthenium tetroxide; two-phase method
OXIDATION OF ORGANIC NITROGEN COMPOUNDS BY MEANS OF RUTHENIUM TETROXIDE: SELECTIVE PREPARATION OF N-SUBSTITUTED LACTAMS
Tangari, Nicola,Giovine, Maria,Morlacchi, Flaviano,Vetuschi, Claudio
, p. 325 - 328 (2007/10/02)
1-Formyl-, 1-acetyl-, and 1-benzoyl-perhydro-azepines and -azocines are oxidized by RuO4 to the corresponding N-acyllactams; the 1-benzyl analogues also undergo major endocyclic oxidation to 1-benzyllactams.
