Predicting the Right Mechanism for Hypervalent Iodine Reagents by Applying Two Types of Hypervalent Twist Models: Apical Twist and Equatorial Twist

TL;DR

This paper investigates hypervalent iodine reagents' mechanisms by applying apical and equatorial twist models, revealing how different twist modes influence reactivity and stability, especially in Togni reagents.

Contribution

It introduces a comparative analysis of hypervalent twist models to predict reaction mechanisms of iodine reagents, highlighting the importance of mode selection for accurate mechanistic understanding.

Findings

Togni II's isomerization pathway involves equatorial twist.

Different hypervalent twist models are crucial for predicting reaction mechanisms.

The study enhances understanding of reactivity and stability differences in hypervalent iodine reagents.

Abstract

Since the hypervalent twist followed by reductive elimination is a general reaction pattern for hypervalent iodine reagents, mechanistic studies about the hypervalent twist step provide significant guidance for experiments. Our previous work showed there are two types of hypervalent twist models, i.e. apical twist and equatorial twist. We applied both hypervalent twist models to explain the isomerization mechanism of two important electrophilic trifluoromethylating reagents, Togni I and Togni II. To the best of our knowledge, there are less detailed studies about the different twist modes between both reagents, which are important to predict the right reaction mechanism and especially, understand well the differences of reactivity and stability. Here, we successfully identified Togni II's isomerization pathway via equatorial twist, and suggested different hypervalent twist models should be considered to predict the right mechanisms of reactions with hypervalent iodine reagents.