86065-10-3Relevant articles and documents
Carbamate as an accelerating group in intermolecular Pauson-Khand reaction
Asano, Shota,Itto-Nakama, Kaori,Arimoto, Hirokazu
, (2020)
The Pauson-Khand reaction (PKR) is a powerful means for the construction of cyclopentenones. However, its applications have been limited to the intramolecular version of this reaction because poor yield and regioselectivity are often the major problems in intermolecular PKR. Here we describe that a carbamate moiety in alkene substrate accelerates this intermolecular PKR. The reaction of N-4-dimethylaminophenyl O-allyl carbamate with alkyne-cobalt complex gave cyclopentenones in high yield (up to 90%) and regioselectivity (>9:1).
CaI2-Catalyzed direct transformation of: N -Alloc-, N -Troc-, and N -Cbz-protected amines to asymmetrical ureas
Tran, Van Hieu,Kim, Hee-Kwon
, p. 14093 - 14101 (2019/09/18)
A novel and facile CaI2-catalyzed direct synthesis of asymmetrical ureas from N-Alloc-, N-Troc-, and N-Cbz-protected amines is developed. In this study, the efficient reaction of Alloc-, Troc-, and Cbz-carbamates with amines in the presence of catalytic CaI2 successfully generated various asymmetrical ureas. This catalytic synthetic procedure provided the desired ureas via reactions of these protected aromatic and aliphatic amines with various amines in high yields without side products. This suggests that novel direct synthesis of ureas from Alloc-, Troc-, and Cbz-carbamates can be a promising approach for the synthesis of useful ureas.
N-methylimidazole-catalyzed synthesis of carbamates from hydroxamic acids via the lossen rearrangement
Yoganathan, Sabesan,Miller, Scott J.
, p. 602 - 605 (2013/04/11)
An efficient, one-pot, N-methylimidazole (NMI) accelerated synthesis of aromatic and aliphatic carbamates via the Lossen rearrangement is reported. NMI is a catalyst for the conversion of isocyanate intermediates to the carbamates. Moreover, the utility of arylsulfonyl chloride in combination with NMI minimizes the formation of often-observed hydroxamate-isocyanate dimers during the sequence. Under the present conditions, lowering of temperatures is also possible, enabling a mild protocol.
