H. D. Verkruijsse
Utrecht University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by H. D. Verkruijsse.
Synthesis of Acetylenes, Allenes and Cumulenes#R##N#Methods and Techniques | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
More than a century ago Glaser described the oxidation with air of phenylacetylene to diphenylbutadiyne [1]. The original procedure using preformed copper acetylide has evolved to a number of variants in which the acetylene is oxidized with oxygen or air in the presence of catalytic amounts of copper (I)halide.
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
One of the most commonly used laboratory methods for the preparation of sp2- nitriles is the Rosenmund-von Braun reaction [1], The procedure involves heating of an aryl or hetaryl bromide or iodide with copper(I) cyanide at elevated temperatures, using high-boiling solvents such as DMF. 1-Bromo-l-alkynes (RC=C-Br) react under milder conditions to give alkynenitriles [2]
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
{\text{RX + CuCN }} \to {\text{ RC}} \equiv {\text{N + CuX}}
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
.
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
In 1972 Kumada [1] and Corriu [2] reported the cross-coupling of olefmic and aryl haliDEs with alkyl- and arylmagnesium haliDEs in the presence of nickel compounds, such as dichloro [1,2-bis(diphenylphosphino)ethane] nickel(II) (NiCl2-dppe) and nickel acetylacetonate (Ni(acac)2). Somewhat later coupling reactions were carried out with other organometallic compounds unDEr the influence of various nickel and palladium catalysts.
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
“Contrathermodynamic” conversion of allylic, propargylic and other reactive chlorides or bromides into the corresponding iodides is readily achieved by heating with an alkali iodide in a suitable organic solvent. These reactions, which take place in the absence of any catalyst, proceed to completion thanks to the slight solubility of the alkali chloride or bromide in the applied solvent.
Archive | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
The reaction of acidic acetylenes such as phenylacetylene with formaldehyde and secondary amines was reported by Mannich and Chang in 1933 [1].
Synthesis of Acetylenes, Allenes and Cumulenes#R##N#Methods and Techniques | 1999
Lambert Brandsma; H. D. Verkruijsse; S. F. Vasilevsky
In 1975 Japanese investigators [1] reported the coupling of acetylene and some derivatives with a number of sp 2-halides under the joint influence of palladium (II) chloride and copper (I) iodide. Somewhat earlier, in the same year, two other research groups [2,3] had communicated similar couplings under different conditions, using only palladium catalysts. Such sp to sp 2-couplings were earlier only possible under forced conditions (Stephens-Castro couplings with copper acetylides [4, 5]). Couplings of free acetylenes with iodoheteroaromates in the presence of potassium carbonate and catalytic amounts of metallic copper or Cui have been reported by a research group in Novosibirsk [11].