Intramolecular aromatic 1,5-hydrogen transfer in free radical reactions III. Reactivity of diaryl ketones, ethers, thioethers, sulfoxydes, and sulfones. An experimental and theoretical study

Sandor Karady; Jordan M Cummins; J J Dannenberg; Emma del Rio; Peter G Dormer; Benjamin F Marcune; Robert A Reamer; Tomas L Sordo

doi:10.1021/ol027301t

Intramolecular aromatic 1,5-hydrogen transfer in free radical reactions III. Reactivity of diaryl ketones, ethers, thioethers, sulfoxydes, and sulfones. An experimental and theoretical study

Org Lett. 2003 Apr 17;5(8):1175-8. doi: 10.1021/ol027301t.

Authors

Sandor Karady¹, Jordan M Cummins, J J Dannenberg, Emma del Rio, Peter G Dormer, Benjamin F Marcune, Robert A Reamer, Tomas L Sordo

Affiliation

¹ Process Research Department, Merck Research Laboratories, Merck and Company, P.O. Box 2000, Rahway, New Jersey 07065, USA. sandor_karady@merck.com

PMID: 12688712
DOI: 10.1021/ol027301t

Abstract

[reaction: see text] Experiments show that free radical hydrogen shift is significant in the Pschorr cyclization of diphenyl ethers (X = O) and thioethers (X = S) and does not take place with sufoxides (X = SO) and sulfones (X = SO(2)). DFT calculations of the product ratios, activation energies, rate constants for H-transfers, and ring-closings at the UB3PW91/6-31G(d,p) level are in excellent agreement with the experimental results reported here and elsewhere in the literature.