Rearrangement of Biaryl Monoaminocarbenes via Concerted Asynchronous Insertion into Aromatic C−H Bonds
摘要:
The biphenyl and binaphthyl diisopropylaminocarbenes were found to be only transient species that spontaneously and quantitatively rearrange into the corresponding aminofluorenes. DFT calculations confirm that these insertion reactions of aminocarbenes into proximal aromatic C-H bonds require only a moderate energy barrier and support a concerted, strongly asynchronous, mechanism dominated by C-arom-C-carbene proton transfer.
pK<sub>a</sub>s of the conjugate acids of N-heterocyclic carbenes in water
作者:Eleanor M. Higgins、Jennifer A. Sherwood、Anita G. Lindsay、James Armstrong、Richard S. Massey、Roger W. Alder、AnnMarie C. O'Donoghue
DOI:10.1039/c0cc03367g
日期:——
pKa values of 19.8–28.2 are reported for the conjugate acids of a large series of NHCs in water. The effects of ring size, N-substituent and C(4)–C(5) saturation on pKa are discussed.