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A direct dehydroxylative and decarboxylative coupling between a large number of allylic alcohols and alkynoic acids was realized affording 1,4-enyne motifs in high efficiency. In this reaction, calcium-promoted C–OH bond cleavage was crucial, which facilitated the sequential ­decarboxylation, and thus enabled the palladium-catalyzed allyl­–alkynyl coupling, which occurred in an environmentally benign manner tolerating a wide variety of functional groups. This protocol has been successfully used in preparing anticancer active rooperol derivatives in gram scale.

A practical palladium/calcium catalytic system was developed for dehydrative allylation with unactivated allylic alcohols. EtOH solvent with a H2O additive was identified as powerful medium to accelerate proton transfer. This catalytic system and environmentally benign medium enabled a variety of soft carbonic nucleophiles and allylic alcohols to react smoothly at room temperature with water as the only byproduct. A wide spectrum of allylic compounds bearing a variety of functional groups can be obtained with high to excellent yields.

A highly efficient Pd/Ca catalytic system for the directly dehydrative cross-coupling of allylic alcohols with terminal alkynes was developed. This calcium salt cocatalyst facilitates the oxidative addition of the palladium catalyst (1 mol %) to the C-OH bond. Then, the in situ-generated hydroxide ion deprotonates the terminal alkynes to promote the formation of the allylalkynylpalladium intermediate, liberating water as the only byproduct. This proposed mechanism is also supported by density functional theory calculations. An anticancer agent was prepared from inexpensive starting materials on a 10 g scale.

A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent E selectivity.

A novel calcium-catalyzed in situ dehydrative cross-coupling reaction of propargylic alcohols with 1,3-dicarbonyl compounds was developed. This catalytic system can suppress the competitive Meyer–Schuster rearrangement, control regioselectivity, and enable the desired process to occur under solvent-free conditions at room temperature with water as the only byproduct. A variety of vicinal tertiary and all-carbon quaternary centers can be obtained in high yields with broad functional group tolerance.

An environmentally benign protocol that affords propargylic sulfones containing highly congested carbon centers from easily accessible alcohols and sulfinic acids with water as the only byproduct is reported. The reaction proceeded via an in situ dehydrative cross-coupling process by taking advantage of the synergetic actions of multiple hydrogen bonds rather than relying on an external catalyst and/or additives to achieve high product distribution.

Allylic sulfones, owning to their widespread distributions in biologically active molecules, received increasing attention in the past few years. However, the synthetic method under mild conditions is still a challenging task. In this paper, we report a sulfinic acids ligation with allylic alcohols via metal-free dehydrative cross-coupling. Both aliphatic and aromatic sulfinic acids react with various allylic alcohols to deliver the desired allylic sulfones in high yields with excellent selectivity. This carbon–sulfur bond formation reaction is highly efficient and practical since it works under metal-free, neutral, aqueous media and at room temperature in which the products even can be obtained by simple filtration without the need for organic extraction or column chromatography. Water is found to be essential for the success of this carbon–sulfur bond formation reaction. DFT calculations imply that water acts as promoter in this transformation via intermolecular hydrogen bonds., Despite the biological importance of sulfones, available synthetic methods usually involve toxic metals and reagents or harsh conditions. Here, the authors report an environmentally benign procedure for the metal-free carbon-sulfur bond formation of allylic sulfones in neutral aqueous medium at room temperature.

A barium-catalyzed C-OH/P-H dehydrative cross-coupling protocol for the construction of C-P bonds was developed. This reaction was performed in an environmentally benign manner with water as the only by-product. A variety of allylic phosphorus compounds can be isolated in good to excellent yields.

A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent

A novel strategy for the preparation of allylic phosphorus ylides directly from Morita–Baylis–Hillman (MBH) alcohols in an environmentally benign manner was developed. With the assistance of a calcium catalyst, the SN2′ process between phosphines and allylic alcohols occurred smoothly, delivering allylic phosphorus salts and calcium-stabilized hydroxide ions. Then, in situ deprotonation gave the allylic phosphorus ylides with water as the only byproduct. Functionalized 1,3-diene moieties can be conveniently obtained by trapping the ylides through a Wittig olefination.