Bis(iodozincio)methane, prepared from lead-catalyzed reaction of zinc with diiodomethane, afforded 1,3-diketones either by the reaction with acyl cyanides or by palladium catalyzed reaction with acyl chlorides. Reaction with adipoyl dichloride gave cyclic enol ester by intramolecular reaction.
Gold(I)-Catalysed Cyclisation of Alkynoic Acids: Towards an Efficient and Eco-Friendly Synthesis of γ-, δ- and ϵ-Lactones
作者:Danila Gasperini、Lorenzo Maggi、Stéphanie Dupuy、Richard M. P. Veenboer、David B. Cordes、Alexandra M. Z. Slawin、Steven P. Nolan
DOI:10.1002/adsc.201600575
日期:2016.12.7
The improved synthesis of γ‐, δ‐ and ϵ‐lactones using a dinuclear N‐heterocyclic carbene (NHC)‐gold(I) catalyst is reported. This solvent‐free process provides access to γ‐ and δ‐lactones in high regio‐ and stereoselectivity. Reactions were performed at low catalyst loadings and without the need for any additives. The use of a digold pre‐catalyst provides a new synthetic route to functionalised ϵ‐lactones
Group VIII carbamoyl complexes as catalysts for alkyne hydrocarboxylation and electrochemical proton reduction
作者:Chandan Kr Barik、Malcolm E. Tessensohn、Richard D. Webster、Weng Kee Leong
DOI:10.1016/j.jorganchem.2019.03.019
日期:2019.7
A series of group VIII carbamoyl complexes, [M(2-NHC(O)C5H4N)(CO)2(2-SC5H4N)] [where M = Fe, Ru and Os], was found to be efficient and regioselective catalysts for the intramolecular hydroxycarboxylation of α,ω-alkynoic acids, yielding exocyclic enol lactones for ring sizes up to 7 atoms, and endocyclic enol lactones for ring sizes up to 12 atoms. They also catalysed the regioselective intermolecular
发现了一系列的VIII族氨基甲酰基配合物,[M(2-NHC(O)C 5 H 4 N)(CO)2(2-SC 5 H 4 N)] [其中M = Fe,Ru和Os]是有效的区域选择性催化剂,可用于α,ω-链烷酸的分子内羟基羧化反应,可制得环尺寸最大为7个原子的环外烯醇内酯,而环尺寸最大可形成12个原子的内环烯醇内酯。他们还催化了炔丙醇和羧酸之间的区域选择性分子间羟基羧化反应,形成β-氧代酯。这些络合物还可以在质子还原中充当电催化剂,对其氧化还原电位的评估表明,铁络合物比钌或类似物的效率要高得多。
Regioselective cyclization of α,ω-alkynoic acids catalysed by TpRu complexes: synthesis of endocyclic enol lactones [Tp = hydrotris(pyrazolyl)borate]
作者:Manuel Jiménez-Tenorio、M. Carmen Puerta、Pedro Valerga、F. Javier Moreno-Dorado、Francisco M. Guerra、Guillermo M. Massanet
DOI:10.1039/b106647c
日期:——
The Ï-enynyl complex [TpRuC(Ph)C(Ph)CCPh}(PMeiPr2 )] efficiently catalyses the regioselective cyclization of α,Ï-alkynoic acids to yield endocyclic enol lactones having ring size up to 12 atoms.
Platinum pincercomplexes featuring an SCS indenediide backbone have been prepared and evaluated in the catalyticcycloisomerization of alkynoic acids and N‐tosyl alkynylamides. One of the platinum complexes significantly outperforms its palladium analogue for the formation of 6‐ and 7‐membered rings. The catalytic system takes advantage of the alkynophilicity of Pt and of the non‐innocent character