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A method for the conjunctive functionalization of vinyl boronate complexes with electrophiles is described. The overall process represents a three-component coupling between a vinyl boronic ester, carbon nucleophile and an electrophile, thus affording complex multifunctionalized products from simple starting materials. The diastereoselectivity (syn or anti) of this process is strongly dependent upon the nature of the electrophile.

In the presence of acetic acid, trifurylphosphine and CO (2 atm), palladium catalyses the conversion of a range of enynes to cyclic δ,γ-unsaturated carboxylic acids in good yield.

The expedient enantioselective synthesis of 5 bisabolane sesquiterpenes has been achieved using a common, one-pot lithiation–borylation reaction of secondary benzylic carbamates and either protodeboronation or oxidation to give the natural products in fewer than 5 steps, with high yield and >94 : 6 er.

Carbocyclic methyl and silyl enol ethers (TBDMS is optimum) can be synthesised regiospecifically by ring closing metathesis using the ‘second generation’ Grubbs ruthenium carbene catalyst in combination with molecular sieves.

Dichloroketene reacts, via a [3,3]-sigmatropic rearrangement, with camphor-derived 1,3-oxathianes of α,β-unsaturated aldehydes to give macrocyclic thiolactones in high yield and with complete transfer of chirality. The rearrangement is stereospecific.

Low yields are obtained when the Baylis–Hillman reaction is conducted in the presence of an imidazolium-based ionic liquid due to direct addition of the deprotonated imidazolium salt to the aldehyde. Ionic liquids are evidently not inert.

Triphenylarsine catalyses the formation of epoxides from carbonyl compounds and tosylhydrazone salts. This convergent synthesis gives complete trans selectivity for all aldehyde and tosylhydrazone salt coupling partners.

Conditions have been found for the efficient palladium mediated cyclisation–carbonylation of bromodienes to give γ,δ-unsaturated acids.

Bicyclic ester 2, a key intermediate in the first total synthesis of (+)-pyripyropene A 1, was synthesised from geraniol in 11 steps, utilising an epoxy-olefin biomimetic cyclisation as the key step.

DBU, which is normally regarded as a hindered and non-nucleophilic base, is in fact the optimum catalyst for the Baylis–Hillman reaction, providing adducts at much faster rates than using DABCO or 3HQD; the scope of the Baylis–Hillman reaction is enhanced using this catalyst and implications of this finding are discussed.

CuII–bisoxazoline complexes catalyse the asymmetric Diels–Alder cycloaddition of α-thioacrylates with cyclopentadiene to give the cycloadducts in up to 92% yield, 88% de and >95% ee for the endo product; deprotection gives good yields of (1S,4S)-norbornenone with high enantioselectivity.

Calculations show that the unexpected low phenyl migratory aptitude observed in reactions of mixed alkyl-aryl boranes with benzylic sulfur ylides can be attributed to (1) a conformational issue, (2) the reduction of the usual neighbouring effect of the phenyl in the transition state by the benzylic nature of the migrating terminus, (3) steric hindrance suffered by the larger phenyl group migrating to the hindered migrating terminus and this despite (4) the increase in the barrier to alkyl migration by the presence of a 'non-migrating' phenyl on the boron atom.

Catalytic asymmetric cylopropanation of enones has been achieved using diazo compounds, catalytic quantities of a metal catalyst and a camphor-derived thioacetal; this sulfide shows exceptionally high levels of enantioselectivity.

Allylic amines (as their protonated ammonium salts) can be epoxidised with high syn diastereoselectivity and regioselectivity at the proximal alkene in substrates with several double bonds using Oxone. The protonated ammonium cation activates the Oxone by hydrogen bonding, thus promoting the oxidation of groups within the vicinity of the complex.

The catalytic asymmetric oxidation of unfunctionalised alkenes is achieved by a non-transition metal catalysed process; just 5 mol% of the binaphthyl-based iminium salt 1 is sufficient to catalyse the oxidation of alkenes to epoxides with moderate to good enantioselectivity.

The formation of highly enantioenriched boronic esters through both stoichiometric and catalytic methods has received much attention over the past decade. Accordingly, the transformations of the boronic ester moiety into other functional groups is of considerable interest in synthesis. Specifically, transformations which retain the high enantioenrichment of the starting boronic ester, either through a stereoretentive or a stereoinvertive pathway, lead to the formation of new C-C, C-O, C-N, C-X, or C-H bonds at stereogenic centres. This feature article summarises the current state of the art in stereospecific transformations of both secondary and tertiary boronic esters into other functionalities and groups, whilst considering critically the transformations that are currently unattainable and would represent future advances to the field.