Homogeneous and Nanoparticle Gold-Catalyzed Hydrothiocyanation of Haloalkynes
作者:Xiaojun Zeng、Bocheng Chen、Zhichao Lu、Gerald B. Hammond、Bo Xu
DOI:10.1021/acs.orglett.9b00728
日期:2019.4.19
homogeneous and heterogeneous nanoparticle gold-catalyzed addition of sulfur nucleophiles to alkynes was developed. More specifically, gold-catalyzed hydrothiocyanation of haloalkynes gave good yields and good stereoselectivity of vinyl thiocyanates. Furthermore, a sulfur-based gold catalyst (PPh3AuSCN) has shown a unique reactivity in gold-catalyzed reactions such as the cyclization of N-propargylic amides
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
New SCS Pd pincercomplexes featuring a noninnocent indenediide backbone show high catalytic activity in cycloisomerization. A variety of alkylidenelactams (five- to seven-membered rings) have been prepared efficiently from N-tosyl alkynylamides, and good results have also been obtained with challenging alkynoic acids.
Cyclization of alkynoic acids with gold catalysts: a surprising dichotomy between AuI and AuIII
作者:Hassina Harkat、Albert Yénimégué Dembelé、Jean-Marc Weibel、Aurélien Blanc、Patrick Pale
DOI:10.1016/j.tet.2008.10.112
日期:2009.2
ω-Acetylenic acids, substituted or not at their acetylenic end, could be efficiently cyclized to γ- or δ-alkylidene lactones in the presence of AuCl and K2CO3. In contrast AuCl3 led to lactone dimers, probably through cyclization and reductive dimerization. These AuI and AuIII catalyzed cyclizations were totally regioselective and most often highly stereoselective.
在AuCl和K 2 CO 3的存在下,可以在其乙炔基末端取代或不取代的ω-乙炔酸有效地环化为γ-或δ-亚烷基内酯。相反,AuCl 3可能通过环化和还原性二聚而导致内酯二聚体。这些Au I和Au III催化的环化反应完全是区域选择性的,并且通常是高度立体选择性的。
A case study of proton shuttling in palladium catalysis
作者:Julien Monot、Paul Brunel、Christos E. Kefalidis、Noel Ángel Espinosa-Jalapa、Laurent Maron、Blanca Martin-Vaca、Didier Bourissou
DOI:10.1039/c5sc04232a
日期:——
Thanks to mechanistic studies, the catalytic performance of SCS indenediide Pd pincer complexes has been spectacularly enhanced using catechol additives as proton shuttles.