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Coumaraz‐2‐on‐4‐ylidene: Ambiphilic N‐Heterocyclic Carbenes with a Tunable Electronic Structure
Author(s) -
Song Hayoung,
Kim Hyunho,
Lee Eunsung
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201804249
Subject(s) - carbene , chemistry , electrophile , aryl , transition metal carbene complex , electronic effect , nucleophile , combinatorial chemistry , computational chemistry , reactivity (psychology) , rhodium , chemical shift , photochemistry , organic chemistry , catalysis , medicine , alkyl , alternative medicine , pathology
Herein, a coumaraz‐2‐on‐4‐ylidene ( 1 ) as a new example of an ambiphilic N‐heterocyclic carbene, having electronic properties that can be fine‐tuned, is reported. The N‐carbamic and aryl groups on the carbene carbon center provide exceptionally high electrophilicity and nucleophilicity simultaneously to the carbene center, as evidenced by the 77 Se NMR chemical shifts of their selenoketone derivatives and the CO stretching strengths of their rhodium carbonyl complexes. Since the precursors of 1 could be synthesized from various functionalized Schiff bases in a practical and scalable manner, the electronic properties of 1 can be fine‐tuned in a quantitative and predictable way by using the Hammett σ constant of the functional groups on aryl ring. The facile electronic tuning capability of 1 may be applicable to eliciting novel properties in main‐group and transition‐metal chemistry.