1567842-73-2Relevant articles and documents
Constructing Saturated Guanidinum Heterocycles by Cycloaddition of N-Amidinyliminium Ions with Indoles
Allred, Tyler K.,Shaghafi, Michael B.,Chen, Pan-Pan,Tran, Quan,Houk,Overman, Larry E.
supporting information, p. 7618 - 7623 (2021/10/12)
We report that structurally complex guanidinium heterocycles can be prepared in one step by regio- and stereoselective [4 + 2]-cycloadditions of N-amidinyliminium ions with indoles or benzothiophene. In contrast to reactions of these heterodienes with alkenes, density functional theory (DFT) calculations show that these cycloadditions take place in a concerted asynchronous fashion. The [4 + 2]-cycloaddition of N-amidinyliminium ions (1,3-diaza-1,3-dienes) with indoles and benzothiophene are distinctive, as related [4 + 2]-cycloadditions of N-acyliminium ions (1-oxa-3-aza-1,3-dienes) are apparently unknown.