Chemical Science Blog

We’ve just published the first article in our new ‘Accepted Manuscript’ service. Atsuhiro Osuka, from Kyoto University, Japan, and colleagues are the first Chemical Science authors to benefit from their research being made available in citeable form even more rapidly. Read their Edge article for free: Phosphorus complexes of a triply-fused [24]pentaphyrin 

All Chemical Science authors are now given the option of publishing their research as an Accepted Manuscript. An Accepted Manuscript is an unedited and unformatted version of an article that is published shortly after acceptance. It is available as a downloadable pdf file. It is then replaced by the fully edited and formatted Advance Article. Find out more >

Paul Floreancig’s group at the University of Pittsburgh has developed a stereoselective heterocycle synthesis starting from allylic alcohols.

Treatment of allylic alcohol (1) with rhenium heptoxide leads to the formation of a perrhenate ester (2) that undergoes a rearrangement to form a mixture of two ester stereoisomers (3 and 4). Cyclisation occurs through nucleophilic addition to the reactive oxo-carbenium intermediate to form a mixture of kinetic products (5 and 6). Owing to the fact that that ring formation is reversible in some cases, stereoselectivity arises from one product being more thermodynamically favourable; a discovery that the Floreancig group have developed to their advantage.

Stereoselectivity is increased in substrates that are better able to stabilise the oxocarbenium ion of the acyclic intermediate and thermodynamics dictate the stereochemical orientation of the anomeric centre formed.

Youwei Xie, from the Floreancig group, has extended this methodology to enable the construction of bi- and tricyclic structures in good to excellent levels of stereocontrol.

This methodology enables the synthesis of complex three-dimensional architectures from starting materials containing pre-installed stereocentres. Additionally, a number of biologically active compounds such as didemniserinolipids and pinnatoxins contain bridged bicyclic cores that could be accessed using this chemistry.

Posted on behalf of Alice E. Williamson, Chemical Science web writer.

Download the group’s Chemical Science Edge article for free.

Incorporating selenium into a polymer backbone can improve the polymer’s electron transport and could lead to improved organic electronics, reports scientists from the UK and Australia.

Ambipolar conjugated polymers, which can transport both holes and electrons, are of great interest as a method to mimic silicon-based logic circuits. Thiophene copolymers have been shown to be good hole transporters but are let down by their ability to transport electrons. 

Replacing thiophene with selenophene results in a significant reduction in polymer band gap, enabling the polymers to effectively transport electrons as well as holes. The resulting polymers display one of the highest hole mobilities reported for any device structure.

Download the Chemical Science Edge article to find out more.