Efficient Cs2CO3-promoted solution and solid phase synthesis of carbonates and carbamates in the presence of TBAI
作者:Ralph N Salvatore、Feixia Chu、Advait S Nagle、Elona A Kapxhiu、Richard M Cross、Kyung Woon Jung
DOI:10.1016/s0040-4020(02)00286-7
日期:2002.4
Novel solution and solid-phase methods for the synthesis of carbonates and carbamates were developed using cesium bases and TBAI via a three-component coupling. Cesium carbonate not only promoted successful carbonylations of alcohols and carbamations of amines, but also suppressed common side reactions traditionally seen using existing protocols. Various alcohols and amines were examined, using a wide
The direct reductive amination of electron-deficient amines with aldehydes: the unique reactivity of the Re2O7 catalyst
作者:Braja Gopal Das、Prasanta Ghorai
DOI:10.1039/c2cc33185c
日期:——
An unprecedented direct reductive amination of electron-deficient amines such as Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, ArSO2-, Ar2PO-, etc. protected amines with aldehydes is achieved using the Re2O7 catalyst and silanes as the hydride source. Excellent regioselective mono-alkylation and chemoselective reductive-amination were observed.
Direct Alkynylation of Thiophenes: Cooperative Activation of TIPS-EBX with Gold and Brønsted Acids
作者:Jonathan P. Brand、Jérôme Waser
DOI:10.1002/anie.201003179
日期:——
United we stand! Cooperativeactivation of the hypervalent‐iodine reagent TIPS‐EBX with a gold catalyst and a Brønstedacid allowed the first direct ethynylation of thiophenes at room temperature (see scheme; TFA=trifluoroacetic acid). The obtained ethynylthiophenes are important building blocks for organic dyes and electronic materials.
A simple zincchloridemediated cyclization of ynamidyl N‐carbamates or 2‐ynamidyl‐(hetero)arylcarboxylates is achieved under mild reaction conditions, leading to the synthesis of useful heterocyclic scaffolds, 3H‐oxazol‐2‐ones and pyrrolo‐oxazin‐1‐ones, with good yields.
Carbamate Synthesis Using a Shelf‐Stable and Renewable C
<sub>1</sub>
Reactant
作者:Zoltán Dobi、B. Narendraprasad Reddy、Evelien Renders、Laurent Van Raemdonck、Carl Mensch、Gilles De Smet、Chen Chen、Charles Bheeter、Sergey Sergeyev、Wouter A. Herrebout、Bert U. W. Maes
DOI:10.1002/cssc.201900406
日期:2019.7.5
4‐Propylcatechol carbonate is a shelf‐stable, renewable C1 reactant. It is easily prepared from renewable 4‐propylcatechol (derived from wood) and dimethyl carbonate (derived from CO2) using a reactive distillation system. In this work, the 4‐propylcatechol carbonate is used for the two‐step synthesis of carbamates under mild reaction conditions. In the first step, 4‐propylcatechol carbonate is treated