The unexpected rearrangement of N-allyl-2-phenyl-4,5-dihydrooxazole-4-carboxamides in the presence of LiHMDS has been found. The key features are: (1) the net reaction consisted of 1,3-migration of the N-allyl group, (2) the rearrangement produced a congested aza-quaternary carbon center, (3) both cyclic and acyclic substrates underwent the unexpected rearrangement to afford products in moderate to
A mild, copper-catalysed amide deprotection strategy: use of tert-butyl as a protecting group
作者:Vikki Evans、Mary F. Mahon、Ruth L. Webster
DOI:10.1016/j.tet.2014.07.080
日期:2014.10
Mild methods for the deprotection of organic substrates are of fundamental importance in synthetic chemistry. A new room temperature method using a catalytic amount of Cu(OTf)2 is reported. This allows use of the tert-butyl group as an amide protectinggroup. The methodology is also extended to Boc-deprotection.
Remote Amino Acid Recognition Enables Effective Hydrogen Peroxide Activation at a Manganese Oxidation Catalyst
作者:Laia Vicens、Giorgio Olivo、Miquel Costas
DOI:10.1002/anie.202114932
日期:2022.2.7
Aminoacid supramolecular recognition in the 2nd coordination sphere of a bioinspired manganesecatalyst allows efficient enzyme-like activation of H2O2 by locating the carboxylic acid moiety in proper position to access the 1st coordination sphere of the metal.
仿生锰催化剂的第二配位层中的氨基酸超分子识别通过将羧酸部分定位在适当的位置以进入金属的第一配位层,从而实现 H 2 O 2的有效酶样活化。
Conversion of Medium-Sized Lactams to α-Vinyl or α-Acetylenyl Azacycles via N,O-Acetal TMS Ethers
synthesized from 7- to 9-membered lactams and 6- to 9-membered lactams via N,O-acetal trimethylsilyl (TMS) ethers. Organocopper and organostannane reagents afforded reasonable yields for the respective N-acyliminium ion vinylation and acetylenylation intermediates generated from N,O-acetal TMS ethers in the presence of a Lewis acid.