Forty years ago--the first paper

In the 1950s and 1960s, chemistry was seen as a romantic and thrilling scientific discipline that promised to improve people's lives beyond measure. It was during this exciting time that The Chemical Society decided to launch a new journal aimed at disclosing the latest research results in a quick, direct, and brief way. Organic chemist, Professor Hans Wynberg of the University of Groningen in the Netherlands wrote the very first paper in Chemical Communications. What was it like to do research then? Wynberg, now 82 years of age, gave Bert Meijer some insights when he recently visited him in his lake-side home in Groningen.     

Forty years of in vitro evolution

It has been 40 years since Spiegelman and co-workers demonstrated how RNA molecules can be evolved in the test tube. This result established Darwinian evolution as a chemical process and paved the way for the many directed evolution experiments that followed. Chemists can benefit from reflecting on Spiegelman's studies and the subsequent advances, which have taken the field to the brink of the generation of life itself in the laboratory. This Review summarizes the concepts and methods for the directed evolution of RNA molecules in vitro.     

Reversal of diastereofacial selectivity in hydride reductions of N-tert-butanesulfinyl imines

A variety of N-tert-butanesulfinyl imines were reduced with NaBH4 in THF containing 2% water to provide the corresponding secondary sulfinamides in high yield and diastereoselectivity. By using the same sulfinyl imine starting materials and changing the reductant to L-Selectride, the stereoselectivity could be efficiently reversed to afford the opposite product diastereomer in high yield and selectivity.     

Pd-catalyzed silicon hydride reductions of aromatic and aliphatic nitro groups

[reaction: see text] Room-temperature reduction of aromatic nitro groups to amines can be accomplished in high yield, with wide functional group tolerance and short reaction times (30 min) using a combination of palladium(II) acetate, aqueous potassium fluoride, and polymethylhydrosiloxane (PMHS). Replacing PMHS/KF with triethylsilane allows aliphatic nitro groups to be reduced to their hydroxylamines.     

Highly stereoselective synthesis of cyclic primary amines via hydride reductions.

The Reduction of p,p'-dimethoxybenzhydryl imines of substituted cyclohexanones with lithium tri-sec-butyl or tri-ethylborohydride and subsequent cleavage of the resulting secondary amines with formic acid affords the corresponding axial cyclohexyl primary amines with high stereoselectivity.     

Synthesis and hydride reductions of chiral cyclic β-iminosulfoxides

The hydride reductions of chiral N-(2-p-tolylsulfinyl)cyclohexylidene phenyl amines 3A and 3B (epimers at C-2), and of N-1-(2-p-tolylsulfinyl)cyclohexenyl benzyl amine, 4, are highly stereoselective, yielding only the corresponding cis-aminosulfoxides.     

Regioselective reductions of 23-epoxy acetals with lithium aluminum hydride: A reinvestigation.

Treatment of 2,3-epoxy acetals with lithium aluminum hydride gave the corresponding 2-hydroxy acetals, instead of the previously reported 3-hydroxy acetals.     

Forty years of quasicrystals: a bumpy road to triumph

Structural Chemistry - On April 8, 1982, Dan Shechtman conducted an electron diffraction experiment on an aluminum/manganese alloy. The diffraction pattern showed tenfold symmetry although the...     

Forty years of research on osmolyte-induced protein folding and stability

Most organisms that have adapted to environmental stresses have done so by production and accumulation of certain small organic molecules, known as osmolytes that arose by natural selection and have the ability to stabilize intracellular proteins against the environmental stress. It is well known that osmolytes stabilize proteins and induce folding of aberrant proteins and therefore, it is of therapeutic use for a large number of protein misfolding diseases. Thus, it is very important that the present knowledge of the ability and mechanism of osmolyte-induced protein folding and structural stabilization should reach to researchers working in different avenues. In around 40 years of research, we have gained great advances in various aspects of protein folding and structural stabilization induced by osmolytes. To summarize and discuss the original findings, many short review articles and few long reviews have also been available but almost all have focuses on specific aspects. To get a clear picture of the effect of osmolytes on protein folding and structural stabilization, it is necessary for the benefits of the general readers, to combine and discuss all findings made during its 40 years of life. This review article is therefore, designed to give a collective knowledge on almost all facets of the progresses made on osmolyte-protein interaction to-date.     

Forty years of progress in the study of the hydrogen bond

Structural Chemistry - The author looks back at developments over the last few decades concerning the H–bond. The list of atoms involved as proton donor and acceptor has broadened...     

Forty years of industrial developments in the field of isotactic polyolefins

The interest for the stereospecific polymerization of olefins discovered by prof. Natta in 1954 was so high that only a few years elapsed between the discovery and the commercialization of polypropylene. The polypropylene discovery generated a tremendous scientific and technological effort for the development of the catalyst, the process, the products. The fundamental achievements in the polypropylene technology had a significant impact over the polyolefin technology in general. Thanks to it, polyolefinic polymers, copolymers and rubbers, polyefinic based materials and alloys via heterogeneous Ziegler-Natta catalyst polymerization are today largerly the most important family of plastic materials. The ability to vary melt flow and the broad properties range of these materials, the excellent thermal and physical-mechanical properties of isotactic polyolefins together with the favorable economics and their full and easy recyclability widen the concept of monomaterial application fuelling their dynamic expansion since the early sixties.     

An examination of hyperconjugative and electrostatic effects in the hydride reductions of 2-substituted-4-tert-butylcyclohexanones

To better understand electronic effects on the diastereoselectivity of nucleophilic additions to the carbonyl group, a series of 2-X-4-tert-butylcyclohexanones (X = H, CH(3), OCH(3), F, Cl, Br) were reacted with LiAlH(4). Reduction of ketones with equatorial substituents yields increasing amounts of axial alcohol in the series for X [H < CH(3) < Br < Cl < F < OCH(3)]. These data cannot be explained by steric or chelation effects or by the theories of Felkin-Anh or Cieplak. Instead, an electrostatic argument is introduced: due to repulsion between the nucleophile and the X group, axial approach becomes energetically less favorable with an increase in the component of the dipole moment anti to the hydride approach trajectory. The ab initio calculated diastereoselectivities were close to the experimental values but did not reproduce the relative selectivity ordering among substituents. For reduction of ketones with axial substituents, increasing amounts of axial alcohol are seen in the series for X [Cl < Br < CH(3) < OCH(3) < H < F]. After some minor adjustments are made, this ordering is consistent with both the electrostatic model and Felkin-Anh theory. Cieplak theory cannot account for these data regardless of adjustments. Ab initio calculated diastereoselectivities were reasonably accurate for the nonpolar substituents but were poor for the polar substituents.