First preparation of allyl vanadium reagents in a mixed solvent of THF and HMPA (HMPA = hexamethylphosphoric triamide) and their application to allylation of carbonyl compounds
作者:Yasutaka Kataoka、Isamu Makihira、Kazuhide Tani
DOI:10.1016/0040-4039(96)01579-1
日期:1996.9
Allylation of carbonylcompounds with allyl bromide mediated by a vanadium(II) complex in a mixedsolvent of THF and HMPA (HMPA = hexamethylphosphorictriamide) has been accomplished. Coordination of HMPA to a vanadium metal is essential for the stabilization of the allylvanadium species.
The Barbier‐type allylation of aldehydes and ketones can be carried out with both unsubstituted and γ‐substituted allyl bromides using only a catalytic amount (0.1 equiv.) of In metal in [bmim][Br].
Catalytic Organic Reactions on the Surface of Silver(I) Oxide in Water
作者:Masaharu Ueno、Arata Tanoue、Shū Kobayashi
DOI:10.1246/cl.140818
日期:2014.12.5
We have developed Ag2O-catalyzed allylation reactions of aldehydes with allylsilanes in water, providing homoallylic alcohols in high yields with high anti-selectivities. It was found that the reac...
Medium-Sized Heterocycle Synthesis by the Use of Synergistic Effects of Ni-NHC and γ-Coordination in Cycloisomerization
作者:Chun-Yu Ho、Lisi He
DOI:10.1021/jo5008477
日期:2014.12.19
an NHC–NiH catalyst and γ-heteroatom chelation were used together as a basis for 1,n-diene termini differentiation and for nγ-exo-trig (head-to-tail) product selectivity. Heterocycles bearing an exocyclic methylene such as oxepines, thiepines, siloxepines, and oxocanes were synthesized from the corresponding 1,n-dienes by a fine-tuning of the NHC properties. The implication of the underlying hypothesis
Allylation Reactions of Aldehydes with Allylboronates in Aqueous Media: Unique Reactivity and Selectivity that are Only Observed in the Presence of Water
Zn(OH)2‐catalyzed allylation reactions of aldehydes with allylboronates in aqueous media have been developed. In contrast to conventional allylboration reactions of aldehydes in organic solvents, the α‐addition products were obtained exclusively. A catalytic cycle in which the allylzinc species was generated through a B‐to‐Zn exchange process is proposed and kinetic studies were performed. The key