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The ring-opening of 2-methylfuran catalyzed by the Lewis acid catalyst tris(pentafluorophenyl)borane in the presence of hydrosilanes was studied by 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 (SV) during the reaction. Our calculations show that the pathway involving the SV 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 bio-derived furans.
This article was published in the following journal.
Name: The Journal of organic chemistry
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Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.
Surgical formation of an opening into the trachea through the neck, or the opening so created.
A group of two-ring heterocyclic compounds consisting of a benzene ring fused to a diazepine ring.
Compounds containing FURANS attached to a nitro group.
Compounds based on a seven-membered ring fused to a five-membered ring. Heat can rearrange them to NAPHTHALENES which have two fused six-membered rings. They are similar to guaiazulenes which are SESQUITERPENES with a six-membered ring fused to a five-membered ring.