Direct Preparation of Heteroaromatic Compounds from Alkenes

Abstract

A series of aromatic heterocycles, thiazoles, imidazoles, and dimethoxyindoles, can be synthesised directly from alkenes via a ketoiodination-cyclisation protocol. The alkene starting materials are themselves easily accessible by many different and well-established approaches, and allow access to various aromatic hetero­cycles with excellent yields and regioselectivity.

heterocycles - alkenes - iodine - iodo ketones - oxidation

References and Notes

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In the reaction of 2-chloro-1-phenylpropan-1-one with benzamidine in the presence of K₂CO₃ at r.t. in DMF, only traces of the corresponding imidazole were detected after
2 h.

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To distinguish between two isomeric aminothiazoles: 5-propyl-4-(3-pyridinyl)-1,3-thiazol-2-amine and 4-propyl-5-(3-pyridinyl)-1,3-thiazol-2-amine.