[3+2] Anionic Cycloaddition of Isocyanides to Acyclic Enamines and Enaminones: A New, Simple, and Convenient Method for the Synthesis of 2,4-Disubstituted Pyrroles
作者:Ilya V. Efimov、Maria D. Matveeva、Rafael Luque、Vasiliy A. Bakulev、Leonid G. Voskressensky
DOI:10.1002/ejoc.201901776
日期:2020.3.8
Herein, a new route toward 2,4‐substituted pyrroles is presented. This is a new, simple, fast, and convenientmethod furnishing 2,4‐substituted pyrroles based on the formal cycloaddition reaction of isocyanides with acyclic enamines or enaminones under basic conditions.
Catalytic Enantioselective Michael Addition of α-Aryl-α-Isocyanoacetates to Vinyl Selenone: Synthesis of α,α-Disubstituted α-Amino Acids and (+)- and (−)-Trigonoliimine A
作者:Thomas Buyck、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201306663
日期:2013.11.25
title reaction in the presence of the catalyst 1 afforded Michael adducts in excellent yields and enantioselectivities. The adducts were readily converted into α,α′‐disubstituted α‐aminoacids. The enantioselective total synthesis of both (+)‐ and (−)‐trigonoliimine A was accomplished using one of the Michael adducts derived from this methodology. M.S.=molecular sieves.
C–H functionalization enabled stereoselective Ugi-azide reaction to α-tetrazolyl alicyclic amines
作者:Surajit Haldar、Subhajit Saha、Sumana Mandal、Chandan K. Jana
DOI:10.1039/c8gc01544a
日期:——
novel reaction produces α-tetrazolyl N-heterocycles directly from N-heterocycles without involving pre-functionalization/pre-oxidation steps. Importantly, the stereoselective reaction involving chiral amines or chiral isocyanides allowed the expeditious syntheses of nucleoside analogs and α-tetrazolyl pyrrolidine in enantioenriched form.
Enantioselective Synthesis of Quaternary Δ<sup>4</sup>
- and Δ<sup>5</sup>
-Dehydroprolines Based on a Two-Step Formal [3+2] Cycloaddition of α-Aryl and α-Alkyl Isocyano(thio)acetates with Vinyl Ketones
作者:Amaiur Odriozola、Mikel Oiarbide、Claudio Palomo
DOI:10.1002/chem.201703526
日期:2017.9.18
of optically active quaternary Δ4‐ and Δ5‐dehydro prolines is developed based on the first catalytic enantioselective conjugateaddition of α‐substituted isocyano(thio)acetates to vinyl ketones that is general for both α‐aryl and α‐alkyl isocyano(thio)acetates. The new tetrasubstituted C−N stereocenter is formed without the need of any metal salt due to a bifunctional tertiary amine/squaramide catalyst
The morpholine and piperazine with their remarkable physical and biochemical properties are popular heterocycles in organic and medicinal chemistry used in rational property design. However, in the majority of cases these rings are added to an existing molecule in a building block approach thus limiting their substitution pattern and diversity. Here we introduce a versatile de novo synthesis of the