A series of domino reactions in which the intramolecular Schmidt reaction is combined with either a Sakurai reaction, an aldol reaction, or both is reported. The Sakurai reaction of an allylsilane with an azido-containing enone under Lewis acidic conditions followed by protonation of the resulting titanium enolate species allowed for a subsequent intramolecular Schmidt reaction. Alternatively, ...

A directed cross-aldol reaction of silyl enol ethers with carbonyl compounds, such as aldehydes and ketones, promoted by a Lewis acid, a reaction which is now widely known as the Mukaiyama aldol reaction. It was first reported in 1973, and this year marks the 40th anniversary. The directed cross-aldol reactions mediated by boron enolates and tin(II) enolates also emerged from the Mukaiyama labo...

conclusions calcined coral/sodium nitrate as a new, efficient, and natural heterogeneous catalyst used in aldol condensation reaction of ketones and aldehydes led to β-hydroxyketones in good to high yields in appropriate condition. materials and methods marine coral (acropora sp.) was washed several times using methanol-ethyl acetate and deionized water and then dried in an oven at 80°c for 48 ...

The first enantioselective catalytic direct cross-aldol reaction that employs nonequivalent aldehydes has been accomplished using proline as the reaction catalyst. Structural variation in both the aldol donor (R1 = Me, n-Bu, Bn, 91 to >99%) and aldol acceptor (R2 = I-Pr, I-Bu, c-C6H11, Et, Ph, 97-99% ee) are possible while maintaining high reaction efficiency (75-88% yield). Significantly, this...

The stereoselective aldol reaction represents one of the major challenges of modern synthetic organic chemistry.1 Many useful methodologies have been reported during the last few decades. For instance, 1,2-asymmetric induction in the aldol reaction of a-alkoxy aldehydes with silyl enol ethers or ketene silyl acetals is well-established.2 The aldol reaction between a-alkoxy aldehydes and a malon...

[reaction: see text] A new one-pot tandem aldol process is described in which a secondary epoxy silyl ether is converted into the 1,5-bis-silyloxy-3-alkanone in good yield. Thus, treatment of the epoxy silyl ether 8 with TBSOTf and base affords the silyl enol ether 9 via non-aldol aldol rearrangement and addition of benzaldehyde and TBSOTf gives the ketone 10 with 4:1 syn selectivity. The diast...

Trichlorosilyl triflate-promoted directed cross-aldol reaction between ketones in the presence of a chiral phosphine oxide as an organocatalyst is described. This is the first enantioselective cross-aldol reaction between simple ketones with good enantioselectivity.

Key words (±)-talatisamine - Diels–Alder reaction [2+2] photo-cycloaddition Lemieux–Johnson oxidation retro-aldol–aldol Wagner–Meerwein rearrangement aza-Prins

The use of homoboroproline as a bifunctional catalyst in the asymmetric aldol reaction has been investigated mechanistically, particularly with respect to tuning the Lewis acidity of boron by in situ esterification with mildly sigma-electron withdrawing diols such as hydrobenzoin and tartrate esters. The stability of simple cyclohexyl and cyclopentyl boronate diol esters shows that the 5-ring b...

An asymmetric total synthesis of callipeltoside A has been accomplished highlighted by a catalytic enantioselective vinylogous aldol reaction and a boron-mediated anti-aldol reaction influenced by remote stereocontrol.