Reviews & Analysis

Nature's enzymes are remarkably efficient at catalysing highly specific reactions with extraordinary selectivity. The ability to design enzymes for any desired reaction is a huge challenge. Here, the advances in the development of artificial enzymes are discussed with a particular focus on the computational advances that bring this challenge closer to reality.

Encapsulating guest molecules inside host structures ranging from soft, flexible enzymes to rigid, porous zeolites has led to developments in many areas, including catalysis, sensing and separation. This Review highlights how metal–organic frameworks — materials formed by linking metal centres with organic ligands — can combine softness with regularity to produce dynamic, yet crystalline, structures that may prove useful for a range of applications.

The development of general synthetic strategies for the prepartion of oligonucleotides and peptides has enabled them to be made routinely — often using automated systems. Making complex oligosaccharides is much less straightforward, but advances in areas such as one-pot multi-step protecting-group manipulations, stereoselective glycosylation protocols and chemo-enzymatic methods are offering new opportunities for carbohydrate chemistry.

Ring-opening metathesis polymerization (ROMP) is a powerful and highly functional-group-tolerant technique for synthesizing polymers. However, this tolerance presents a great challenge for the selective introduction of functional end-groups. This Review discusses currently available end-functionalization strategies and also highlights factors to be considered when choosing the most appropriate approach.

Transition metals can form extremely short bonds with very high bond orders. Bimetallic chromium complexes are the best-known examples, and quintuple bonds have been reported. This Review covers recent developments in the synthesis and theoretical description of quintuply bonded transition metal coordination compounds.

The most stable fullerenes obey the isolated-pentagon rule (IPR): hexagons of carbon atoms entirely surround pentagons to minimize strain. Recently, some examples of fused-pentagon fullerenes have been reported and this Review summarizes current work to stabilize non-IPR fullerenes.

Chemical methods of achieving asymmetric protonation are classified according to reaction mechanism, with a view to developing a greater understanding of this most fundamental of asymmetric processes, and thus improving the potential for its application in synthesis.

The simplicity and broad applicabilty of atom transfer radical polymerization make it a rapidly developing area of synthetic polymer chemistry. Here, the fundamentals of the technique are discussed, along with how it can be used to synthesize macromolecules with controlled molecular architecture, and how their self-assembly can create nanostructured functional materials.

The use of protecting groups has been, and remains, instrumental in the development of organic synthesis. However, designing protecting-group-free strategies offers the challenge of developing useful new chemoselective processes as well as being inherently more step- and atom-economic.

Molecules with a Möbius geometry are not found in nature, and have thus been a target for synthetic chemists since the first prediction of its existence in 1964. This review summarizes recent successes in synthesizing these fascinating forms, with particular emphasis on expanded porphyrins.

Advances in computational methods have enabled the trends in reactivity for transition metal and alloy catalysts to be described theoretically. This review discusses some of the first examples of how such knowledge can be used to design solid catalysts.