Deprotection of heteroaromatic carbamates via a base-catalyzed methanolysis
摘要:
A simple and mild method for the deprotection of heteroaromatic carbamates via methanolysis using a catalytic amount of base such as sodium methoxide, DBU, or Verkade's base (proazaphosphatranes) is presented. Carbantate protecting group of an aliphatic amine is not affected under these conditions. (c) 2006 Elsevier Ltd. All rights reserved.
Access to β-Keto Esters by Palladium-Catalyzed Carbonylative Coupling of Aryl Halides with Monoester Potassium Malonates
作者:Signe Korsager、Dennis U. Nielsen、Rolf H. Taaning、Troels Skrydstrup
DOI:10.1002/anie.201304072
日期:2013.9.9
New tricks for an old dog: The Pd‐catalyzed carbonylative α‐arylation of monoethyl potassiummalonates with aryl bromides and reactive aryl chlorides provides a simple and direct route to aryl β‐ketoesters. Because only stoichiometric amounts of carbon monoxide are employed, the method is ideal for the introduction of carbon isotopes into more complex structures.
C–H activation dependent Pd-catalyzed carbonylative coupling of (hetero)aryl bromides and polyfluoroarenes
作者:Zhong Lian、Stig D. Friis、Troels Skrydstrup
DOI:10.1039/c4cc09303h
日期:——
The carbonylativecoupling of aryl and heteroaryl bromides with polyfluoroarenes via palladium-catalyzed C-H activation is presented. This transformation proceeds efficiently at moderate reaction temperatures and does not require strong base or reactive intermediates. A nearstoichiometric amount of CO is sufficient and the methodology can thus be easily expanded to include the preparation of [(13)C]-acyl
way: A formal [4+2] cycloaddition between various cyclobutanones and indoles proceeded efficiently under Lewis acid catalysis (see scheme; PG = protecting group). The regioselectivity of the reaction could be controlled in such a way that each of the two possible regioisomers of a cycloaddition product could be synthesized selectively. The usefulness of this reaction for the total synthesis of hydrocarbazole
A Palladium-Catalyzed Carbonylative-Deacetylative Sequence to 1,3-Keto Amides
作者:Dennis U. Nielsen、Signe Korsager、Anders T. Lindhardt、Troels Skrydstrup
DOI:10.1002/adsc.201400545
日期:2014.11.24
AbstractAn efficient three‐component reaction involving carbon monoxide with a range of aryl bromides and N‐substituted acetoacetamides is reported for the synthesis of β‐keto amides. This transformation is promoted by Pd‐catalysis followed by an acid‐mediated deacetylation upon work‐up, enabling a large number of β‐keto amides to be isolated. Finally, d2‐13C‐dyclonine could be synthesized in three steps utilizing the developed catalytic system as the key step.magnified image