Ligands aminothiol

In their efforts to construct a library of norephedrine aminothiol ligand analogues, Pericas and co-workers treated spiroaziridinium salts with sulfur nucleophiles to give /3-aminothioacetates (Equations 11 and 12) <2001SL1155>. The yield was not reported for thioacetate 38. The acetyl group was easily reduced with DIBAL-H resulting in the desired compounds. 

A new class of efficient aminothiol ligands has been used in asymmetric alkenyl addition to aldehydes with very low catalytic loading of 1 mol%.114 Efficient formation of chiral (T )-allylic alcohols with ees of up to 99% has been achieved in the presence of (43). 

Several Pd11 complexes with thiolate or thioether derivative ligands have been studied to be applied in the hydroxycarbonylation reaction.394 Aminothiolate complexes of palladium with PPh3 catalyze the conversion of styrene to 2-phenylpropionic acid in high yield and excellent regioselectivity.644 Under mild conditions and in the presence of a catalytic amount of an S, TV-chelated palladium or//zo-amino-arenethiolate complex, styrene reacts with CO and oxalic acid or water to selectively give 2-phenylpropanic aid in high yield.645... 

Seebach et al. (154) showed that a 0-isopropylidene-2,3-dihydroxy-l, 1,4,4-tetraphenyl-l,4-diol (TADDOL)-derived aminothiolate serves as a moderately effective ligand for the catalyzed conjugate addition of Grignard reagents to cyclic enones. The catalyst, synthesized from the lithiothiolate and CuCl, exhibits optimal selectivities under a slow addition protocol (2 h), Eq. 124. 

The simplest organic ligands of this type are mercaptoamines (aminothiols) 451 (R = H), their alkyl (aryl) derivatives 451 (R = Aik, Ar), and their aromatic analogues 452 [1, vol.2] ... 

It appeared that the effieieney of the catalyst depends on the nature and the proportion of the crosslinking agent (eatalyst presenting 70% of EGDMA was more efficient than this with 30% of EGDMA and for DVB a decrease in conversion and ee was observed). It depended also on the specifie surfaee, the nature of the ligand (aminoalcohol or aminothiol) and on the... 

Wipf and Ribe developed a catalytic asymmetric variant of the aldehyde addition process employing chiral aminoalcohols and aminothiols as catalytic ligands [91]. Danishefsky and coworkers used this methodology in a total synthesis of (+)-halichlorine [92], and Porco s group applied it in a recent synthesis of the salicylate antitumor antibiotic lobatamide C [93]. 

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