A novel, efficient synthesis of N-aryl pyrroles via reaction of 1-boronodienes with arylnitroso compounds

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

Regioisomeric and Substituent Effects upon the Outcome of the Reaction of 1-Borodienes with Nitrosoarene Compounds

“…As reported previously, 9 initial investigations into the reaction between the dienyl boronate 1 and nitrosobenzene 2 resulted in the formation of the unexpected N-phenylpyrrole 3a instead of a mixture of regioisomeric oxazine cycloadducts (Scheme 2). Given that such reactions tend to lack high regiocontrol, 2 the efficiency of the pyrrole formation was intriguing and clearly required further study and explanation.…”

“…9 In addition to the possible postfunctionalisation of the resulting cycloadducts, we expected that tuning of the electronic properties of the boronated group through the introduction of various substituents on boron 10 would provide an insight into the control of the regioselectivity of the [4+2] cycloaddition reaction, and therefore, the subsequent transformation of the resulting cycloadducts. Herein, we report the full details of these studies, especially the impact of varying the nature of both the borodiene and dienophile substituents upon the reaction outcome, and hence, discuss the mechanistic implications of the results.…”

Recent Advances in Boron‐Substituted 1,3‐Dienes Chemistry: Synthesis and Application

“…Carboni et al published several papers focused on application of B‐substituted heterodendralenes in the Diels–Alder reactions. [3]‐1‐Heterodendralenes, by analogy to the corresponding carbotrienes, have been used in a steric controlled synthesis of polycyclic heterocycles as well as for the synthesis of tricyclic imide (Scheme ) …”

Transition metal-free one-pot synthesis of nitrogen-containing heterocycles

“…Recently, an interesting synthesis of N-aryl pyrroles 32 was accomplished via the regioselective Diels-Alder reaction of boronodiene 30 and arylnitroso derivatives 31 in methanol (Scheme 11). The expected pathway of the pyrrole formation was suggested via a [4 + 2] cycloaddition/ring contrac- tion rather than a classical nitroso-Diels-Alder cycloaddition [47].…”