{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Essman JZ"],"funding":["National Institute of General Medical Sciences","NIGMS NIH HHS"],"pagination":["7165-7172"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC11001253"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["146(11)"],"pubmed_abstract":["We report asymmetric potassium-isothiourea-boronate-catalyzed Wittig olefinations of 4-substituted cyclohexanones with non-stabilized phosphorus ylides to afford highly enantioenriched axially chiral alkenes. The optimal catalyst features an unusual macrocyclic amide-potassium-boronate chelate. Kinetic and spectroscopic analyses are consistent with a Lewis acid mechanism for the catalytic olefination that results in the formation of the oxaphosphetane adduct under cryogenic conditions. Thermal fragmentation of the oxaphosphetane to the alkene product occurs after the reaction is complete. Computational studies indicate that cycloaddition proceeds via a stepwise mechanism involving enantiodetermining polar 1,2-addition to afford an intermediate potassium betaine complex."],"journal":["Journal of the American Chemical Society"],"pubmed_title":["Enantioselective Potassium-Catalyzed Wittig Olefinations."],"pmcid":["PMC11001253"],"funding_grant_id":["GM43214","R01 GM132571","GM149244","R37 GM043214","R01 GM043214","R35 GM149244"],"pubmed_authors":["Essman JZ","Jacobsen EN"],"additional_accession":[]},"is_claimable":false,"name":"Enantioselective Potassium-Catalyzed Wittig Olefinations.","description":"We report asymmetric potassium-isothiourea-boronate-catalyzed Wittig olefinations of 4-substituted cyclohexanones with non-stabilized phosphorus ylides to afford highly enantioenriched axially chiral alkenes. The optimal catalyst features an unusual macrocyclic amide-potassium-boronate chelate. Kinetic and spectroscopic analyses are consistent with a Lewis acid mechanism for the catalytic olefination that results in the formation of the oxaphosphetane adduct under cryogenic conditions. Thermal fragmentation of the oxaphosphetane to the alkene product occurs after the reaction is complete. Computational studies indicate that cycloaddition proceeds via a stepwise mechanism involving enantiodetermining polar 1,2-addition to afford an intermediate potassium betaine complex.","dates":{"release":"2024-01-01T00:00:00Z","publication":"2024 Mar","modification":"2025-04-05T12:37:00.391Z","creation":"2025-04-05T12:37:00.391Z"},"accession":"S-EPMC11001253","cross_references":{"pubmed":["38451542"],"doi":["10.1021/jacs.4c00564"]}}