Disrotatory Ring-Opening of Furans Gives Stereocontrol

Autor:	Sukbok Chang, Chinmoy K. Hazra, Jinhoon Jeong, Hyunjoong Kim, Mu-Hyun Baik
Rok vydání:	2019
Předmět:	010405 organic chemistry Organic Chemistry Borane 010402 general chemistry Ring (chemistry) 01 natural sciences Medicinal chemistry 0104 chemical sciences Lewis acid catalysis chemistry.chemical_compound Nucleophile chemistry Furan Intramolecular force Conrotatory and disrotatory Bond cleavage
Zdroj:	The Journal of Organic Chemistry. 84:11061-11067
ISSN:	1520-6904 0022-3263
DOI:	10.1021/acs.joc.9b01627
Popis:	The ring-opening of 2-methylfuran and 2,3-dihydro-5-methylfuran catalyzed by the Lewis acid catalyst tris(pentafluorophenyl)borane in the presence of hydrosilanes was studied using quantum chemical methods. In a previous study, it was suggested that the stereoselective formation of the product is due to a nucleophilic vinylic substitution (SNV) during the reaction. Our calculations show that the pathway involving the SNV reaction is energetically not accessible. Instead, the intramolecular C-O bond cleavage is found to be much more favorable in energy for the ring opening reaction. The experimentally observed excellent stereoselectivity toward the Z-isomer product originates from an intrinsic preference of the furan ring to couple the C-O bond cleavage with a disrotatory motion of the oxygen and carbon fragments. This stereoselective feature is naturally programmed into the furan ring manifold and should be generally exploitable for engineering stereoselective ring-opening processes of bioderived furans.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::aed76cb7fe10b1284978e255f7ecd972 https://doi.org/10.1021/acs.joc.9b01627 Zobrazit plný text záznamu