Lewis Acid Catalyzed Annulation of Donor–Acceptor Cyclopropane and N-Tosylaziridinedicarboxylate: One-Step Synthesis of Functionalized 2H-Furo[2,3-c]pyrroles

Abstract

An efficient MgI2-catalyzed annulation between donor-acceptor cyclopropane and N-tosylaziridinedicarboxylate to access highly substituted 2H-furo[2,3-c]pyrrole bearing two rings and four stereocenters, including one quaternary carbon stereocenter, has been developed. This methodology can be used for the synthesis of biologically active compounds like IKM-159. This work also offers an insight into the mechanism of the annulation process.

Reactivity of Donor‐Acceptor Cyclopropanes with Saturated and Unsaturated Heterocyclic Compounds

“…Recently, our group developed an efficient MgI 2 ‐catalyzed annulation between DACs 17 and N‐tosylaziridine dicarboxylate 18 to access highly substituted 2 H ‐furo,–pyrrole 19 (Scheme ) . The presence of two rings and four stereocenters, including one quaternary carbon stereocenter, in the product makes it a useful precursor for the synthesis of biologically active compounds like IKM‐159, 20 .…”

One‐Pot Synthesis of Oxazolidine Derivatives by [3+2]‐Annulation Reactions of 1‐Tosyl‐2‐phenyl/alkylaziridines with Aryl Epoxides

“…[8] Use of ep-oxides as oxyranyllithiums toward the synthesis of important scaffolds has also been demonstratedb ys everal groups. [11] To the besto fo ur knowledge,t here are no reports availableo nt he synthesis of functionalized oxazolidined erivatives from two strained rings with different functionalities, for example, aziridinea nd epoxide. [10] Recently,o ur group has developed as train-induced synthesis of functionally important heterocycles from cyclopropane-epoxides and cyclopropane-aziridines.…”

(3+3)‐Annulation of Donor–Acceptor Cyclopropanes with Diaziridines

“…This kind of reactivity is predominant for most threemembered rings with two heteroatoms.T hus,i nr eactions involving small ring opening diaziridines act as synthetic equivalents of azomethine imines (synthon II, X = Y = NR). [12] The reported reactions of D-A cyclopropanes with aziridines, [13] oxiranes, [14] oxaziridines [15] led to various products different from (3+ +3)-cycloadducts.Herein, we report the first successful (3+ +3)-annulation of two different saturated three-membered rings exemplified by Lewis acid-induced coupling of D-Ac yclopropanes with diaziridines (Scheme 1c). [11] However, (3+ +3)-annulation of two different saturated three-membered rings has not been reported thus far owing to the difficulties in the selective activation of this reactivity mode.…”