The Cu‐catalyzed Ullmann‐Goldberg cross‐coupling between aryl iodides and oxamates is shown to afford the corresponding N‐aryloxamates with yields ranging from moderate to excellent, when the oxamate precursor incorporates a bulky tertiary alkyl group effectively preventing product degradation under the strongly basic reaction conditions. The final oxamic acids are then generated through the acid hydrolysis of the oxamate in high yields. These acids were then converted into urethanes using PIDA under thermal conditions or a visible‐light Fe‐LMCT process. While electron‐deficient N‐aryl oxamic acids provide urethanes with high efficiencies, electron‐rich counterparts led to diminished yields due to aryl group over‐oxidation induced by PIDA.
Storable N-phenylcarbamate palladacycles for rapid functionalization of an alkyne-encoded protein
作者:Gang Cheng、Reyna K. V. Lim、Carlo P. Ramil、Qing Lin
DOI:10.1039/c4cc02969k
日期:——
Here we report the synthesis of storable N-phenylcarbamate palladacycles that showed robust reactivity in the cross-coupling reaction with an alkyne-encoded protein with a second-order rate constant approaching 19 770 +/- 930 M(-1) s(-1).
Electrochemical ruthenium-catalyzed alkyne annulations by C–H/Het–H activation of aryl carbamates or phenols in protic media
作者:Ruhuai Mei、Julian Koeller、Lutz Ackermann
DOI:10.1039/c8cc07732k
日期:——
Electrooxidative peri-C–H activation was accomplished by versatile ruthenium(II) catalysis in terms of C–H/N–H and C–H/O–H functionalization. Thus, alkyne annulations proved viable with ample scope by organometallic C–Hactivation. The sustainable electrocatalysis exploited electricity, thereby avoiding the use of toxic transition metals as sacrificial oxidants. The robust ruthenium(II)-electrocatalysis
Electrooxidative围-C-H活化是由通用的钌(完成II)催化的C-H / N-H和C-H / O-H官能的条款。因此,通过有机金属的C–H活化,炔烃环行证明在足够的范围内是可行的。可持续的电催化利用电力,从而避免使用有毒的过渡金属作为牺牲氧化剂。鲁棒的钌(II)电催化作用在质子醇/ H 2 O反应介质中,具有极好的位置,区域和化学选择性。
Differential functional theory and molecular docking studies of newly synthesized carbamates
作者:Muhammad Danish、Muhammad A. Raza、Uzma Anwar、Umer Rashid、Zaheer Ahmed
DOI:10.1002/jccs.201800068
日期:2019.11
Four new carbamates (RZ1–RZ4) were synthesized from different amine moieties through reported methods. The reaction was monitored using thin layer chromatography and characterization was done using m.p., fourier‐transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) techniques. Density functional theory (DFT) studies were carried out using Gaussian 09 software to compare the theoretical
Rh(III)-Catalyzed Regioselective Functionalization of C–H Bonds of Naphthylcarbamates for Oxidative Annulation with Alkynes
作者:Xuan Zhang、Weili Si、Ming Bao、Naoki Asao、Yoshinori Yamamoto、Tienan Jin
DOI:10.1021/ol502317c
日期:2014.9.19
A Rh(III)-catalyzed highly efficient and regioselective functionalization of diverse C–H bonds of naphthylcarbamates for oxidative annulation with alkynes has been developed. The annulation with a neutral rhodium catalyst system proceeds through peri C–H bond functionalization of arylcarbamates to give benzoquinoline derivatives, while with a cationic rhodium catalyst system it proceeds through ortho
Synthesis of isocyanates from carbamate esters employing boron trichloride
作者:D. C. D. Butler、H. Alper
DOI:10.1039/a807287f
日期:——
The conversion of carbamate esters to isocyanates and diisocyanates of industrial importance is possible using BCl3 in the presence of Et3N; the reaction is simple in execution and work-up, occurring under mild conditions and affording isocyanates in excellent yields.