Steric protection strategy

Fig. 1S.1S. Steric protection strategy using PEO-b-PDAEMA-b-PMEMA triblock copolymer for preparing core-crosslinked nanospheres using high solids content. (Adapted from [59].)...

Alkenols may be polymerized by group IV catalysts using a mixture of both steric and protective strategies. Aaltonen and co-workers reported the copolymerization of a variety of alkenols with ethylene and propylene using zirconocene/MAO catalysts. 

In principle, the reaction of oxo-Mo(iv) complexes with SAT reagents could produce oxosulfido-Mo(vi) species, especially in the presence of innocent, sterically protective co-ligands. Indeed, this strategy has proved indispensable in the development of scorpionate-based MoHMs (Section 7.4.1.1.3). Related conversions, e.g. of Mo(ii) complexes to sulfido-Mo(iv) species, followed by OAT, may also be useful in the synthesis of oxosulfido-Mo(vi) complexes. Potential sulfur atom donors include elemental sulfur, thiiranes, thiols and phosphine sulfides. However, sulfur s propensity for catenation limits its usefulness in single-atom SAT reactions. To date, thiols and phosphine sulfides have found limited application in such reactions. ... 

The suppression of the thermodynamically favoured decomposition of Mo enzyme active sites is achieved by the stabilization and steric protection afforded by the apoprotein. Co-ligand sterie protection also plays an important role in stabilizing known MoHMs (Seetion 7.4). Unfortunately, the synthesis of sterically encumbered dithiolene ligands, an obvious strategy for... 

Stabilization of triplet carbenes is shown to be better accomplished by steric protection than by electronic effect. However, the latter strategy can be used to stabilize singlet carbenes. ... 

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