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A general, scalable two-step regio- and diastereoselective method has been described for the synthesis of versatile alkaloid-type azetidines from simple building blocks with excellent overall yields. In the kinetically controlled reaction, only the formation of the strained four-membered ring can be achieved instead of the thermodynamically favorable five-membered rings under appropriate conditions. Remarkable functional group tolerance has also been demonstrated. In this paper, we give a new scope of Baldwin's rules by density functional theory (DFT) calculations with an explicit solvent model, confirming the proposed reaction mechanisms and the role of kinetic controls in the stereochemical outcome of the reported transition-metal-free carbon-carbon bond formation reactions.

Semiochemicals are substances or mixtures that carry messages and are used for communication between individuals of the same or different species. Semiochemicals that are used in pest control are called biopesticides. Conventional pesticides, which are generally synthetically derived and unnatural, inactivate or kill the pests, whereas biopesticides are naturally occurring compounds that attract insects to a trap or interfere with their reproduction. There are several advantages to biopesticides. Compared with conventional pesticides, biochemical-based pesticides are often less toxic and therefore have a significantly lower impact on human health and the environment. Moreover, biopesticides are pest-selective and as such do not negatively impact other organisms such as insects, mammals, or birds. Other advantages of biopesticides include high potency, meaning that smaller amounts of biopesticide are required, less resistance by target organisms, and the ability to biodegrade more quickly than conventional...

Cross metatheses of tung oil, a nonedible vegetable oil and α-eleostearic acid ((9Z,11E,13E)-octadeca-9,11,13-trienoic acid, ESA) methyl ester (1), obtained from tung oil containing the same highly unsaturated, conjugated double bonds, have been carried out with cis-1,4-diacetoxy-2-butene (2) using Hoveyda-Grubbs (3-HG2) or Grubbs second or third generation catalysts (3-G2 or 3-G3). The reactions followed by Pd/C-catalyzed hydrogenation give methyl 11-acetoxyundecanoate (4) as a polyester raw material, 1,6-diacetoxy-hexane (5) as a precursor of 1,6-hexanediol (6) polyurethane monomer, and heptyl acetate as a fragrance (7) in 53–99% yields after Pd/C-catalyzed hydrogenation. The one-pot isomerization metathesis of α-linolenic acid ((9Z,12Z,15Z)-9,12,15-octadecatrienoic acid, ALA) methyl ester (7) using 2 as cross coupling agent, RuHCl(CO)(PPh3)3 (9) as isomerization, and 3-G2 as a metathesis catalyst followed by Pd/C catalyzed hydrogenation leads also to the formation of 5 and the homologues of 4 and 7 in ...