The Staudinger ligation provides a means to form an amide bond between a phosphinothioester and azide. This reaction holds promise for the ligation of peptides en route to the total chemical synthesis of proteins. (Diphenylphosphino)methanethiol is the most efficacious of known reagents for mediating the Staudinger ligation of peptides, providing high (> 90%) isolated yields for equimolar coupl...

Reaction of o-azidobenzenesulfonamides with ethyl carbonochloridate afforded the corresponding amide derivatives, which gave 3-ethoxy-1,2,4-benzothiadiazine 1,1-dioxides through an intramolecular aza-Wittig reaction. The reaction was found to be general through the synthesis of a number of benzothiadiazine 1,1-dioxides. Acid-catalyzed hydrolysis of 3-ethoxy-1,2,4-benzothiadiazine 1,1-dioxides f...

A climbing end image algorithm is proposed to locate transition state structures based on the nudged elastic band method. According this algorithm, all intermediate structures, known as images in nudged-elastic-band method, can climb potential energy surface along reaction path state. The number of be reduced because are located limited region. This method was applied simplified Wittig reaction...

In this paper we demonstrate a method of synthesizing oligoenes of diisopropyldipropargylmalonate, [CH2][bx][CH2] (x ) 2, 3, 4, 5), in which the “b” repeat unit is identical to the five-membered ring formed in a tail-to-tail cyclopolymerization of diisopropyldipropargylmalonate, and methylene groups are capping the ends. For example, a “degenerate” metathesis reaction between the “monomer”, [CH...

Modeling, optimization, and the realization of an electroosmotically driven chemical microsynthesis system for Wittig reactions are presented. Essential for good functioning of the chemical liquid reaction system is controllability of the supplied chemicals, independently of the reservoir heights. System analysis turned out to be crucial for designing new improved chips. In the article the main...

2-Alkyl cyclohexenones are useful intermediates for organic synthesis. The Wittig reaction of a series of aldehydes with (cyclopropylmethyl)triphenylphosphonium bromide delivered the corresponding alkenyl cyclopropanes. UV irradiation in the presence of Fe(CO)5 converted the alkenyl cyclopropanes to the 2-substituted cyclohexenones. This approach enabled a three-step synthesis of the tricyclic ...

We report the first catalytic asymmetric cyanation of N-Boc ketoimines, which enables highly enantioselective synthesis of oxindole based α-amino nitriles. An unprecedented tandem aza-Wittig/Strecker reaction is also developed, emerging as a promising strategy for the catalytic asymmetric cyanation of ketoimines formed in situ from achiral ketones.

The synthesis of the 5-hydroxyproline derivatives 3a and 3b using cyclobutane serine analogs 1 and 2 as starting materials is reported. This process occurs with moderate cis/trans selectivity. A mechanism for this reaction is also proposed. Cyclobutane serine analog 1 was tested in tandem Michael and Wittig-like reactions, providing some evidence of the mechanism proposed.

Heteroaryl substituted allyl and homoallyl alcohols were synthesised with two different method. Synthesis of bis-allyl ethers and homoallyl ethers were carried out via reaction of allyl bromide with allyl alcohols and homoallyl alcohols, respectively. [2.3]-Wittig Rearrangement reactions of heteroaryl substituted bis-allyl ethers were investigated using GC/MS techniques. In these reactions two ...