A Highly Stereocontrolled, One-Pot Approach toward Pyrrolobenzoxazinones and Pyrroloquinazolinones through a Lewis Acid-Catalyzed [3 + 2]-Cycloannulation Process

Abstract

We report herein a stereocontrolled [3 + 2]-cycloheteroannulation of bis-silyl dienediolate 1 with 2-aminobenzoic acid- and 2-aminobenzamide-derived imines to furnish highly substituted pyrrolo[1,2-a]benzoxazinones 3 and pyrrolo[1,2-a]quinazolinones 4, respectively, in good overall yields. This one-pot process rapidly generates molecular complexity and comprises a Lewis acid-catalyzed, vinylogous Mannich reaction of 1 followed by an intramolecular N,O-acetal- and N,N-aminal formation, respectively, which proceeds with good to excellent stereocontrol.

A Highly Stereoselective Synthesis of Tetrahydrofurans

“…In the context of a rapid and diversity‐oriented approach toward complex heterocycles we have recently established a novel bis(silyl) dienediolate 1 , which easily reacted with aryl imines carrying a secondary nucleophilic group in the ortho position to yield tricyclic pyrrolobenzoxazoles, pyrrolobenzoxazinones, and pyrroloquinazolinones in a domino reaction. Furthermore, 1 could as well behave as a formal 1,2‐dinucleophile and react with simple and readily available imines and enals to furnish pyrroloquinolines and 1‐cyclopentenyl‐α‐keto esters, respectively, with good chemical yields and stereoselectivity.…”

The PIFA-initiated oxidative cyclization of 2-(3-butenyl)quinazolin-4(3H)-ones – an efficient approach to 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones

“…1-Aryl-substituted tetrahydropyrrolo[1,2- a ]quinazolin-5-ones can be also obtained by a Brønsted acid-catalyzed annulation of arylcyclopropane aldehydes and N′ -anthranilic hydrazides [ 31 ], as well as by Sm(OTf) 3 -catalyzed stereoselective [3 + 2] cycloaddition of bis-silyldienediolate and imines, in turn synthesized from anthranylamides and benzaldehydes [ 32 ].…”

A Complex Catalytic Reaction Caught in the Act: Intermediates and Products Sampling Online by Liquid μ‐Beam Mass Spectrometry and Theoretical Modeling

“…In the currents tudy we highlight the first application of the approach on an important typeo f modularm ulticomponent reaction as at est case for the technique. [21][22][23][24] We have recently studied some details of the overall reactiond isplayed in Scheme 1, which belongs to af amily of recently developedr eaction schemes to efficiently build up complexo rganic structures. The products and intermediates, as well as the reaction mechanisms are investigatedh ereb y means of laser desorption liquid m-beam mass spectrometry supported by quantum chemical calculations.…”