Wittig reaction

Ebook "Stereoselective alkene synthesis (Topics in Current chemistry, Volume 327)" highlight the recent development of the widely used methods for olefin synthesis, namely Wittig reactions (Chapter 7) and olefin metathesis (Chapter 6). For olefin metathesis, the focus is put on its applications in complex natural product synthesis.

283p coduathanh1122 27-03-2024 4 1   Download

Ebook "Investigation of reactions involving pentacoordinate intermediates: The mechanism of the Wittig reaction" discovery of an effect common to representative examples of all Li salt-free Wittig Reactions. The implications of such a universally applicable effect are that all such Wittig reactions occur through the same mechanism. Although the Wittig reaction was first discovered in 1953, its reaction mechanism has never been definitively settled with many different variants proposed and disproved.

245p nhanphanguyet 28-01-2024 3 2   Download

The three-component reaction of benzoic acid derivatives, (N -isocyanimino)triphenylphosphorane, and trichloroacetyl isocyanate in a 1:1:1 ratio in CH3 CN occurred at room temperature, and the 5-aryl-N -(trichloroacetyl)- 1,3,4-oxadiazole-2-carboxamide derivatives produced were formed in high yields. The reaction proceeded smoothly and cleanly under mild reaction conditions and no side reactions were observed. The structures of the products were confirmed by IR, 1 H NMR, 13 C NMR, mass spectroscopy, and elemental analysis.

6p langthannam 29-12-2021 5 0   Download

This paper reviews literature over 25 years’ activity on phosphoryl carbanion reagents and shows that these compounds are powerful tools in organic chemistry. The main target of this review is to outline some of the reactive peculiarities that make this class of compounds powerful tools in the synthesis of 5- and 6-heterocyclic compounds and/or substituted heterocycle phosphor esters. The importance of these latter compounds in pharmacology is also discussed.

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We report a novel microwave-assisted two-step, one-pot protocol for the synthesis of olefins (alkenes) via Wittig reaction. The reaction was carried out under solvent-free conditions using basic alumina both as a heterogeneous catalyst and a solid support. Varieties of aromatic aldehydes were converted into their corresponding olefins within 30–50 min with good to excellent yields. An excellent predominance of E -isomers over Z -isomers (up to 100% E-selectivity) for all the olefin products was observed.

8p tudichquannguyet 29-11-2021 19 1   Download