Synthetic efforts toward the chlorinated aza-propellane alkaloid acutumine (1) are described. The key vicinal quaternary centers were constructed by a photochemical [2 + 2] cycloaddition reaction of a furanyl-tetrahydroindolone. Dihydroxylation of the [2 + 2] product enabled a tandem retro-aldol/intramolecular ketalization reaction, which revealed the aza-propellane core of 1 while generating a...

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...

silica ferric hydrogensulfate is an efficient heterogeneous catalyst for the cyclization of 2- aminochalcones to the corresponding 2,3-dihydroquinolin- 4(1h)-ones. this intramolecular aza michael reaction was carried out in high yields using chalcones bearing of electron donating and electron withdrawing groups. the catalyst is reusable without significant decreases in its activity after four t...

[m.n] Multinuclear ferrocenophanes prepared by aza-Wittig reaction of bisiminophosphoranes derived from 1,1'-diazidoferrocene and isophthaladelhyde or 2,5-diformylthiophene, behave as efficient electrochemical and chromogenic chemosensor molecules for Zn2+, Pb2+, and Hg2+ metal cations. Whereas the OSWV of receptor 3, bearing two m-phenylene units in the bridges, display one oxidation peak, rec...

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 ...

A strained aza-dibenzocyclooctyne was prepared via a high-yielding synthetic route. Copper-free, strain-promoted click reaction with azides showed excellent kinetics, and a functionalised aza-cyclooctyne was applied in fast and efficient PEGylation of enzymes.

A highly enantioselective construction of delta- and gamma-lactone[2,3-b]piperidine skeletons was accomplished by tandem aza-Diels-Alder reaction-hemiacetal formation-oxidation from N-Tos-1-aza-1,3-butadienes and aliphatic dialdehydes.