title: Carreira alkynylations with paraformaldehyde. a mild and convenient protocol for the hydroxymethylation of complex base-sensitive terminal acetylenes via alkynylzinc triflates.
abstract: A new synthetic protocol for the hydroxymethylation of terminal acetylenes is described that involves stoichiometric Carreira alkynylation with solid paraformaldehyde (HO[CH2O]nH) in PhMe at 60 °C. Significantly, the method can be successfully applied on acetylenes that possess base-sensitive ester functionality and heterocyclic rings that readily undergo metalation. While N-methylephedrine (NME) is generally the best Zn(OTf)2-coordinating ligand for promoting hydroxymethylation, TMEDA can serve as a replacement.
authors.affiliation: The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen's University Belfast , Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK.
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Hale
authors.forename: Ziyue
authors.initials: Z
authors.lastname: Xiong
authors.forename: Liping
authors.initials: L
authors.lastname: Wang
authors.forename: Soraya
authors.initials: S
authors.lastname: Manaviazar
authors.forename: Ryan
authors.initials: R
authors.lastname: Mackle
mesh_terms: D000478:Alkylation; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D004809:Ephedrine / Q000031:analogs & derivatives* / Q000737:chemistry; D004952:Esters; D005557:Formaldehyde / Q000737:chemistry*; D008024:Ligands; D008698:Mesylates / Q000737:chemistry*; D008745:Methylation; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*
chemical_list: D000480:Alkynes; D004952:Esters; D008024:Ligands; D008698:Mesylates; D011108:Polymers; D005557:Formaldehyde; C041707:N-methylephedrine; D004809:Ephedrine; C012077:trifluoromethanesulfonic acid; C003043:paraform