Current Organic Chemistry - Volume 14, Issue 15, 2010

This special issue is aimed to illustrate the key advances provided by the synergy between modern computational methodologies and experimentation in organic chemistry. The recent history of computer development and engineering has confirmed Moore's law, which states that the processing power of computers increases in an exponential rate. Such progress has allowed a revolutionary qualitative transition fro Read More

The vibrational motions of a molecule in its equilibrium or during a chemical reaction provide a wealth of information about its structure, stability, and reactivity. This information is hidden in measured vibrational frequencies and intensities, however can be unraveled by utilizing quantum chemical tools and applying the Cal-X methods in form Vib-Cal-X. Vib-Cal-X uses the measured frequencies, complements them to a co Read More

Pentadienyl cation electrocyclizations have played key roles in the syntheses of many complex organic molecules. Herein, theoretical studies on the mechanisms of pentadienyl cation electrocyclizations are reviewed and general principles applicable to the design of such reactions are highlighted.

In this article, recent computational studies focused on double group transfer reactions and related processes are summarized. The reported results clearly indicate that these transformations can be considered as a subclass of pericyclic reactions occurring concertedly, with high activation barriers and synchronicity values, and through highly symmetric transition states. Interestingly, the aromatic nature of the latt Read More

Interconversions between α-oxoketenes, imidoylketenes and α-oxoketenimines, thioacylketenes and acylthioketenes, vinylketenes and acylallenes, isocyanates, and thioacylisocyanates and acylisothiocyanates take place by means of 1,3-shifts of substituents, which are facilitated by electron-rich migrating groups, especially those containing lone pairs on the migrating atoms. A bonding interaction between the lone pair orbital Read More

An overview of recent studies, which show the important role played by computational chemistry in explaining and predicting the behavior of a great variety of systems is presented. The first example illustrates the useful interplay experiment-theory which allowed to unambiguously characterize the X2(CH3)7 + (X = Si, Ge, Sn, Pb) cations as paradigmatic examples of molecular systems involving pentacovalently boun Read More

This minireview is addressed to readers with a background in basic organic chemistry and spectroscopy, but without a specific knowledge of NMR, ECD, VCD and ORD. Herein we summarize the role of quantum mechanical ab initio prediction of spectral properties in NMR and chiroptical spectroscopies. Illustrative examples of the application of prediction of chemical shifts and scalar couplings to the determination of che Read More

Q2MM is a method designed to allow application of molecular mechanics calculations to transition states in chemical reactions. It is one of the few methods available that allow determination of a complete set of low-energy transition states for medium-sized systems, and thereby gives a unique opportunity to investigate kinetic selectivity, in particular stereoselectivity. The current review will give an outline of the procedure, an ov Read More

Collaborative work between experimentalists and computational chemists have demonstrated a stong synergy which allowed the rationalization of allenyl azide chemistry and permited the development of an efficient synthetic tool aimed at the preparation of several alkaloids. Saturated allenyl azides undergo a reaction cascade involving key diradical intermediates that follow the Curtin- Hammett model whereas unsaturated all Read More

Recent computational and experimental studies of organic reactions that show sequential transition structures on the potential energy surfaces are reviewed. The specific focus is on pericyclic and pseudopericyclic reactions. A distinction is made between symmetric and unsymmetric systems; in the former, the intrinsic reaction coordinate connects the two transition structures. The importance of the change in the reaction coordi Read More