RESUMO
A reagent-controlled diastereodivergent copper-catalyzed borylative difunctionalization is reported. The formation of Lewis adducts that guide selectivity is commonly invoked in organic reaction mechanisms. Using density functional theory calculations, we identified BpinBdan as a sterically similar and less Lewis acidic alternative to B-2pin2. Using a newly developed borylative aldol domino reaction as the proof-of-concept, we demonstrate a change in stereochemical outcome by a simple change of borylating reagent - B2pin2 affords the diastereomer associated with coordination control while BpinBdan overturns this mode of binding. We show that this strategy can be generalized to other scaffolds and, more importantly, that BpinBdan does not alter the diastereomeric outcome of the reaction when coordination is not involved. BpinBdan can be viewed as a mechanistic probe for coordination in future copper-catalyzed borylation reactions.
RESUMO
Left unchecked, plant-parasitic nematodes have the potential to devastate crops globally. Highly effective but non-selective nematicides are justifiably being phased-out, leaving farmers with limited options for managing nematode infestation. Here, we report our discovery of a 1,3,4-oxadiazole thioether scaffold called Cyprocide that selectively kills nematodes including diverse species of plant-parasitic nematodes. Cyprocide is bioactivated into a lethal reactive electrophilic metabolite by specific nematode cytochrome P450 enzymes. Cyprocide fails to kill organisms beyond nematodes, suggesting that the targeted lethality of this pro-nematicide derives from P450 substrate selectivity. Our findings demonstrate that Cyprocide is a selective nematicidal scaffold with broad-spectrum activity that holds the potential to help safeguard our global food supply.