A crystalline monosubstituted carbene. Issue 12 (December 2018)

• Record Type: Journal Article
• Authors: Nakano, Ryo; Jazzar, Rodolphe; Bertrand, Guy
• Is Part Of: Nature chemistry. Volume 10:Issue 12(2018)
• Page Start: 1196
• Page End: 1200
• Publication Date: 2018-12
• Subjects: Chemistry -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Bioorganic chemistry -- Periodicals; 540
• DOI: 10.1038/s41557-018-0153-1
• Languages: English
• ISSNs: 1755-4330

Abstract

Abstract By flanking a carbene carbon with two substituents, it is possible to synthesize persistent triplet carbenes and isolable singlet carbenes. Isolable singlet carbenes are among the most powerful tools in chemistry, and they have even found medicinal and materials science applications. Between the rich chemistry of disubstituted carbenes and the transient parent carbene are the monosubstituted carbenes that, so far, have only been observed in matrices at very low temperatures of just a few K. Herein, we describe the synthesis of a crystalline monosubstituted carbene. The key for isolating such a species was to design the correct substituent, namely a benzo[c ]pyrrolidino heterocycle, which can single-handedly tame the intrinsic tendency of carbenes towards dimerization. The π-donor ability of the nitrogen atom, coupled with the steric bulk of chemically inert substituents at the two adjacent quaternary carbons, make these scaffolds very attractive for the isolation of a variety of other hitherto elusive electron-deficient species. So far, monosubstituted carbenes have only been spectroscopically characterized at very low temperatures. Now, it has been shown that a bulky, chemically inert, amino substituent is enough to tame the intrinsic tendency of carbenes towards dimerization, enabling their isolation at room temperature.