Development of a novel protocol for chemoselective deprotection of N/O-benzyloxycarbonyl (Cbz) at ambient temperature
摘要:
A novel protocol for the deprotection of N-benzyloxycarbonyl and O-benzyloxycarbonyl groups by nickel boride generated in situ from NaBH4 and NiCl(2)6H(2)O in methanol at room temperature has been developed to give the corresponding amines and phenols. This protocol is chemoselective as groups like chloro, bromo, amide, ester, pyridine, and tert-butyloxycarbonyl moiety are unaffected under these conditions. The deprotection has also been validated in gram scale reactions, to establish the wider appropriateness of this protocol.
Benzyl Protection of Phenols under Neutral Conditions: Palladium-Catalyzed Benzylations of Phenols
作者:Ryoichi Kuwano、Hiroki Kusano
DOI:10.1021/ol800548t
日期:2008.5.1
Benzyl protection of phenols under neutral conditions was achieved by using a Pd(eta3-C3H5)Cp-DPEphos catalyst. The palladium catalyst efficiently converted aryl benzyl carbonates into benzyl-protected phenols through the decarboxylative etherification. Alternatively, the nucleophilic substitution of benzyl methyl carbonates with phenols proceeded in the presence of the catalyst, yielding aryl benzyl
Development of a novel protocol for chemoselective deprotection of N/O-benzyloxycarbonyl (Cbz) at ambient temperature
作者:Mohit Saroha、Komal Aggarwal、Gaurav Bartwal、Jitender M. Khurana
DOI:10.1007/s00706-018-2276-x
日期:2018.12
A novel protocol for the deprotection of N-benzyloxycarbonyl and O-benzyloxycarbonyl groups by nickel boride generated in situ from NaBH4 and NiCl(2)6H(2)O in methanol at room temperature has been developed to give the corresponding amines and phenols. This protocol is chemoselective as groups like chloro, bromo, amide, ester, pyridine, and tert-butyloxycarbonyl moiety are unaffected under these conditions. The deprotection has also been validated in gram scale reactions, to establish the wider appropriateness of this protocol.
Low Pressure Carbonylation of Benzyl Carbonates and Carbamates for Applications in <sup>13</sup>C Isotope Labeling and Catalytic CO<sub>2</sub> Reduction
作者:Craig S. Day、Stephanie J. Ton、Clemens Kaussler、Daniel Vrønning Hoffmann、Troels Skrydstrup
DOI:10.1002/anie.202308238
日期:2023.8.28
Herein, an oxygen atom deletion strategy via sequential Pd-catalyzed decarboxylative carbonylation of carbonates and carbamates to afford esters and amides is reported. Operating under lowpressures (near stoichiometric or substoichiometric), either 13C labeled products are accessed or a proof-of-concept that CO2 formed upon decarboxylation can be reduced in situ and reincorporated as CO is shown.
在此,报道了通过碳酸酯和氨基甲酸酯的连续 Pd 催化脱羧羰基化以提供酯和酰胺的氧原子删除策略。在低压(接近化学计量或亚化学计量)下操作,可以获取13 C 标记的产品,也可以证明脱羧时形成的 CO 2可以原位还原并重新结合为 CO。