Facile, Efficient and Diastereoselective Construction of Indane‐Fused Pyrrolidin‐2‐ones via a Potassium Hydroxide‐Catalyzed Domino Reaction

Abstract

Af acile and efficient potassium hydroxide (KOH)-catalyzed tandem reactioni nvolving sequential Michaela ddition of electron-deficient alkenes with malonic esters,r ing opening of activateda ziridines and lactamization has been described. Ah ighly functionalized indane-fused tricyclic scaffold containing three rings,t hree adjacent stereocenters and aq uaternary center was constructed by the formation of two new C-C bonds and one new C-N bond in adiastereoselectivemanner.Scheme 3. Conversion experiments of the two isomers.Scheme4.Aplausible mechanism for the tandemr eaction.Scheme5.Thetandem reaction of 5l with malonic esters.

Ring-Opening Cyclization (ROC) of Aziridines with Propargyl Alcohols: Synthesis of 3,4-Dihydro-2H-1,4-oxazines

“…Nucleophilic ring-opening followed by cyclization from aziridines provides excellent routes to high-value N -heterocyclic synthetic targets. − There are some interesting reports for the synthesis of 1,4-oxazines from aziridines via ring-opening cyclization with α-diazocarbonyl compounds and propargyl alcohols as well . However, most of them have synthetic limitations, such as the following: strategy cannot provide enantioenriched products (Scheme c), studies were directed toward only alkyl aziridines and aryl propargyl alcohols (Scheme a), or the cyclization step was shown to be endo -selective providing the seven-membered rings (Scheme b)…”