A newly designed PE-supported arsine has been developed as an excellent catalyst for catalytic Wittig-type olefination. Simple ketones, in particular inactive ketones prove to be suitable substrates for the first time. This reaction provides an easy access to di-, tri-, and tetra-substituted olefins in high yield.

A general preparation of new types of benzofurans, benzothiophenes and indoles is realized via chemoselective intramolecular Wittig reactions with the corresponding ester, thioester and amide functionalities using in situ formed phosphorus ylides as key intermediates. The reaction conditions are very mild, and numerous Michael acceptors and commercially available acid chlorides can be applied v...

A small series of 5-(hetero)aryl-modified nucleoside phosphonates was synthesized via an 8-step procedure including a Wittig reaction and Suzuki-Miyaura coupling. An unanticipated anomerization during phosphonate deprotection allowed us to isolate both anomers of the 5-substituted 2'-deoxy-uridine phosphonates and assess their antiviral activity against a broad panel of viruses.

A synthesis of the core ring structure of the fargenin/fargenone family of natural products is presented. The general strategy is based upon biosynthetic speculation and exploits a cascade reaction, which transforms a spirocyclic dienone into the core ring system via a deprotonation-oxy-Michael-Wittig olefination sequence. This study represents the first synthesis work towards this family of na...

2-Acetylcyclopentanone undergoes a smooth reaction with triphenylphosphine and dialkyl acetylenedicarboxylates to produce dialkyl 2-(1-acetyl-2-oxocyclopentyl)-3-(1,1,1-triphenyl-lambda(5)-phosphanylidene)succinates. These compounds undergo intramolecular Wittig reactions in boiling benzene to produce highly strained spirocyclobutene derivatives, which spontaneously undergo ring-opening reactio...

One ring no longer rules them all: Employment of 2.5-10 mol % of 4-nitrobenzoic acid with phenylsilane led to the development of a room temperature catalytic Wittig reaction (see scheme). Moreover, these enhanced reduction conditions also facilitated the use of acyclic phosphine oxides as catalysts for the first time. A series of alkenes were produced in moderate to high yield and selectivity.

The title compound, C(30)H(26)O(2), was prepared by the reaction of a Wittig reagent and 2-methoxy-benzaldehyde. The mol-ecule lies about an inversion centre located at the midpoint of the C-C bond between the inner benzene rings. The crystal structure is stabilized by C-H⋯π inter-actions.

A novel and fully chemo- and stereoselective three component strategy leading to Z-α-chloroacrylates by a Pd(0)-catalyzed reaction of CO (1 atm) with 1,1-dichloro-1-alkenes and various alcohols is disclosed. This catalytic approach compares favourably with the Wittig type strategies as α-chloroacrylates of pure Z configuration are obtained in high yield.