We also calculated continuous potential curves of the ground and

We also calculated continuous potential curves of the ground and excited states of small diatomic molecules by introducing the transferable local sampling method. Although the FC-LSE method is simple, the achievement of chemical accuracy in the absolute energy of larger systems remains time-consuming. The development of more efficient methods for the calculations of ordinary molecules would allow different researchers to make these calculations more easily.”
“In the first successful catalytic asymmetric Diels-Alder reaction in 1979, Koga and colleagues used a chiral aluminum complex as a Lewis add catalyst, but since then, researchers have developed numerous catalytic systems for these reactions. By 2000, several chiral organic compounds, such as the salts of imidazolidinones or TADDOLs, emerged as robust catalysts in the asymmetric Diels-Alder reactions.

Inhibitors,Modulators,Libraries According to frontier molecular orbital theory, most of these catalysts employ a LUMO-lowering strategy as a means of activating electron-deficient dienophiles. Only rarely do chiral catalysts take advantage of the alternative strategy of activating the HOMO.

In this Account we will discuss the development of asymmetric Diels-Alder reactions based on the HOMO-raising effects of chiral amines. First, we show that enamine intermediates formed in situ between an amine catalyst and enolizable aliphatic aldehydes can act as electron-rich dienophiles in inverse-electron-demand Diels-Alder reactions. Inhibitors,Modulators,Libraries We describe the preparation of a variety of oxygen- or nitrogen-containing heterocycles with high optical purity.

Then, we demonstrate that the dienamine species from alpha,beta-unsaturated aldehydes can act either as electron-rich dienes in normal-electron-demand Diels-Alder reactions or as dienophiles Inhibitors,Modulators,Libraries in inverse-electron-demand Diels-Alder reactions. These reactions generally occur with high chemo-, Inhibitors,Modulators,Libraries regio-, and stereoselectivity. Finally, we introduce a new activation mode for Diels-Alder reactions, in which reactive trienamine intermediates derived from 2,4-dienals or even 2,4-dienones play a key role. Notably, we observe remarkab beta,epsilon-regioselectivity and obtain excellent stereocontrol even at the very remote e-reactive center-up to seven bonds away from the chiral center of the amine catalyst.

These results demonstrate that a HOMO-activation strategy via aminocatalysis could become a significant tool in asymmetric Diels-Alder reactions.

In addition, these reactions using enamine, dienamine, or trienamine intermediates produce a diverse array of densely functionalized GSK-3 cyclic scaffolds, which may serve as valuable structures in drug discovery and natural product AZD9291 astrazeneca synthesis.”
“Light interacts surprisingly differently with small particles than with bulk or gas phase materials. This can cause rare phenomena such as the occurence of a “”blue moon”".

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