Exploration of the Synthetic Potential of Electrophilic Trifluoromethylthiolating and Difluoromethylthiolating Reagents. (3rd September 2018)

• Record Type: Journal Article
• Authors: Zhang, Jingjing; Yang, Jin‐Dong; Zheng, Hanliang; Xue, Xiao‐Song; Mayr, Herbert; Cheng, Jin‐Pei
• Is Part Of: Angewandte Chemie. Volume 130:Number 39(2018)
• Page Start: 12872
• Page End: 12877
• Publication Date: 2018-09-03
• Subjects: Difluormethylthiolierung -- Elektrophilie -- Lineare-Freie-Energie-Beziehungen -- Struktur-Aktivitäts-Beziehungen -- Trifluormethylthiolierung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201805859
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The electrophilicity parameters (E) of some trifluoromethylthiolating and difluoromethylthiolating reagents were determined by following the kinetics of their reactions with a series of enamines and carbanions with known nucleophilicity parameters (N, sN ), using the linear free‐energy relationship log k 2 =sN (N+E). The electrophilic reactivities of these reagents cover a range of 17 orders of magnitude, with Shen and Lu's reagent 1 a being the most reactive and Billard's reagent 1 h being the least reactive electrophile. While the observed electrophilic reactivities (E) of the amido‐derived trifluoromethylthiolating reagents correlate well with the calculated Gibbs energies for heterolytic cleavage of the X−SCF3 bonds (Tt + DA), the cumol‐derived reagents 1 f and 1 g are more reactive than expected from the thermodynamics of the O−S cleavage. The E parameters of the tri/difluoromethylthiolating reagents derived in this work provide an ordering principle for their use in synthesis.