A Direct, One Step Synthesis of Imidazoles from Imines and Acid Chlorides: A Palladium Catalyzed Multicomponent Coupling Approach
摘要:
A palladium-catalyzed one-step synthesis of imidazoles from imines and acid chlorides is described. A plausible mechanism for this multicomponent reaction is provided, which explains the selective incorporation of two different imines into the final product with perfect regiocontrol. Overall, this catalytic process provides a modular method to prepare imidazoles directly from building blocks that are all either commercially available or readily generated.
Direct Synthesis of Pyrroles from Imines, Alkynes, and Acid Chlorides: An Isocyanide-Mediated Reaction
作者:Daniel J. St. Cyr、Nicolas Martin、Bruce A. Arndtsen
DOI:10.1021/ol062773j
日期:2007.2.1
[reaction: see text] A direct synthesis of pyrroles from imines, acid chlorides, and alkynes mediated by isocyanides is reported. This reaction proceeds with a range of each of these three substrates, providing a method to generate families of pyrroles in high yield. Mechanistic studies suggest this process proceeds via the generation of imino analogues of munchnones, which can undergo in situ coupling
A very straightforward route to 1-azabicyclo alkaloid scaffolds with several ring sizes is reported. The final bicyclic structures were built through a synthetic scheme that involved (i) the construction of dienic 4-piperidone systems by an imino-Diels−Alder reaction between aminotrienes and N-ω-vinylimines, in the presence of Yb(OTf)3, and (ii) the ring-closing metathesis reaction of these cyclic
A New Use of Wittig-Type Reagents as 1,3-Dipolar Cycloaddition Precursors and in Pyrrole Synthesis
作者:Daniel J. St. Cyr、Bruce A. Arndtsen
DOI:10.1021/ja074330w
日期:2007.10.1
generate a new class of phosphorus-based 1,3-dipolar cycloaddition reagent. These substrates, which are isomeric forms of classic Wittig reagents, undergo cycloaddition reactions in an analogous fashion to 1,3-oxazolium-5-oxides (Munchnones). However, these 1,3-dipoles can be generated in one pot, in a modular fashion, and directly from available reagents, suggesting their potential general utility in
A convenient stereoselective preparation of meso-2,6-disubstituted-4-piperidones has been developed by imino-Diels–Alder reaction of 2-amino-1,3-butadienes with imines in the presence of catalytic amount of Cu(TfO)2.
A convenient stereoselective preparation of meso- and cis-2,6-diarylpiperidin-4-ones has been developed by aza-Diels-Alder reaction catalyzed by l-proline from simple and commercially available starting materials.