Allenamides participate as two-carbon components in an intermolecular [2 + 2 + 2] cycloaddition with alkenes and aldehydes when treated with catalytic amounts of a phosphite gold complex. The reaction is highly regio- and chemoselective, and works with different types of alkenes, including styrenes, enol ethers or enamides, as well as with aromatic and aliphatic aldehydes. Accordingly, differen...

The hydratase-aldolase-catalyzed conversion of trans-o-hydroxybenzylidenepyruvate to salicylaldehyde and pyruvate is an intermediate reaction in the conversion of naphthalene to salicylate by bacteria. Here, a variety of aromatic aldehydes and some nonaromatic aldehydes together with pyruvate have been shown to be substrates for aldol condensations catalyzed by this enzyme in extracts of the re...

A highly selective, radical-mediated (4 + 2) coupling reaction of aldehydes and conjugated olefins has been achieved through asymmetric SOMO-catalysis. A radical-polar crossover mechanism is proposed wherein olefin addition to a transient enamine radical cation and oxidation of the resulting radical furnishes a cation which is vulnerable to nucleophilic addition. A range of aromatic aldehydes a...

Ionic liquid with multi-SO H groups was employed as a catalyst for facile preparation of 3 bis(indolyl)methanes via the one-pot condensation of indole with aldehydes or ketones. Various aliphatic and aromatic aldehydes or ketones were utilized in the reaction and in all situations the desired product were synthesized successfully. The described novel synthesis method propose several advantages ...

The reactions of oxophilic metal phenolates having electron-donating substituents (1a-c) with aromatic aldehydes (2, 3) were selectively condensed at the ortho-position of the starting phenol to afford 2,2'-dihydroxytriphenylmethanes (8-11). This method was also applicable to the preparation of bisphenols (12-17) starting with naphthaldehydes (4, 5) and pyridinecarboxaldehydes (6, 7), but in lo...

An enantioselective aldol reaction of N-propionylthiazolidinethione and representative aldehydes is disclosed. The reaction is catalyzed by [Ni(S,S)-t-BuBox](Otf)2. Enolization is effected by 2,6-lutidine, and TMSOTf facilitates catalyst turnover. Syn diastereoselectivities range from 88:12 to 97:3, and enantioselectivities are 90% or greater. Both aromatic and enolizable aliphatic aldehydes ar...

The development of a catalytic asymmetric method for the direct aminoallylation of aldehydes is described that gives high asymmetric inductions for a broad range of substrates including both aromatic and aliphatic aldehydes. This method allows for direct isolation of unprotected analytically pure homoallylic amines without chromatography. The unique catalyst system developed for this process in...

This review describes the first method to prepare imidazolines from aldehydes and 1,2-diamines by condensation and successive oxidation using NBS in one-pot operation. The reaction proceeds under mild conditions and can be applied to various aromatic and aliphatic aldehydes and 1,2-diamines. The utility of this method is also demonstrated in the total synthesis of spongotine A and the preparati...

C(alpha)-Tetrasubstituted alpha-amino acids are important building blocks for the synthesis of peptidemimetics with stabilized secondary structure, because of their ability to rigidify the peptide backbone. Recently our group reported a new class of cyclic C(alpha)-tetrasubstituted tetrahydrofuran alpha-amino acids prepared from methionine and aromatic aldehydes. We now report the extension of ...

The oxidative cleavage of aliphatic acetals of normal aliphatic aldehydes and substituted aliphatic aldehydes with aliphatic as well as aromatic alcohols with lead tetra acetate in acetic acid, aqueous acetic acid and in acetic acid-benzene medium is first order each in [oxidant] and [acetal] and yields the corresponding esters as the main product The rate of oxidation depends upon the dielectr...