Synthesis of <i>N</i>-(Hetero)aryl Carbamates via CuI/MNAO Catalyzed Cross-Coupling of (Hetero)aryl Halides with Potassium Cyanate in Alcohols
作者:S. Vijay Kumar、Dawei Ma
DOI:10.1021/acs.joc.7b03175
日期:2018.3.2
to N-(hetero)aryl carbamates was developed through CuI/MNAO [2-((2-methylnaphthalen-1-yl)amino)-2-oxoacetic acid] catalyzed cross-coupling of (hetero)aryl chlorides with potassium cyanate in alcohols at 120–130 °C. This method utilizes broadly available substrates to afford various N-(hetero)aryl carbamates in good to excellent yields. Moreover, (hetero)aryl bromides and (hetero)aryl iodides were also
Utilization of carbondioxide in chemical fixation for synthesis of fine chemicals like benzimidazoles, organic carbamates, etc. is in high demand in recent years as carbondioxide is a cost effective, sustainable, and green renewable C1 source. In this article we present the design and synthesis of an organically modified polystyrene bound heterogeneous [PS-Zn(II)-SALTETA] catalyst. The catalyst has
investigated. Aniline was reacted with titanium n‐butoxide (1) in the presence of carbon dioxide (5 MPa) to give the corresponding n‐butyl N‐phenylcarbamate (BPC) in nearly quantitative yield (99 %) within 20 min. Furthermore, 1 could be regenerated upon reaction with n‐butanol during water removal. The recovered 1 could then be reused in a subsequent reaction.
研究了在Ti(OR)4(R = n Bu(1),Me(2),Et(3),n Pr(4))存在下从胺和二氧化碳直接合成氨基甲酸酯的方法。在二氧化碳(5 MPa)存在下,苯胺与正丁醇钛(1)反应,在20分钟内以几乎定量的产率(99%)得到相应的正丁基N-苯基氨基甲酸酯(BPC)。此外,在脱水过程中与正丁醇反应后可再生1。恢复的1 然后可以在后续反应中重复使用。
Reaction of organozinc halides with aryl isocyanates
作者:Haoran Yang、Danfeng Huang、Ke-Hu Wang、Changming Xu、Teng Niu、Yulai Hu
DOI:10.1016/j.tet.2013.01.053
日期:2013.3
Reformatsky reagent, benzylzinc bromide or alkylzinc iodides react with arylisocyanates directly to give corresponding N-substituted carbamates under mild reaction conditions. However, the reaction of allylzinc bromide or propargylzinc bromide with arylisocyanates produces the corresponding N-substituted amides. The reactions provide alternative methods for the synthesis of N-substituted carbamates
Pyridinyl Amide Ion Pairs as Lewis Base Organocatalysts
作者:Julian Helberg、Torsten Ampßler、Hendrik Zipse
DOI:10.1021/acs.joc.0c00114
日期:2020.4.17
Pyridinyl amide ion pairs carrying various electron-withdrawing substituents were synthesized with selected ammonium or phosphonium counterions. Compared to neutral pyridine-based organocatalysts, these new ion pair Lewis bases display superior catalytic reactivity in the reaction of isocyanates with alcohols and the aza-Morita–Baylis–Hillman reaction of hindered electrophiles. The high catalytic activity