Lactam-based phosphoramidites

Figure 2.42 Resistance of lactam-based phosphoramidites la-d toward hydrolysis. Results for the reaction of a 0.0175 M solution in dioxane-1.4 with lOOMequiv. of water at 85°C.

Cramer reported the synthesis of TADDOL-based phosphoramidites 55, which were compared with other already known TADDOL-type phosphoramidites already evaluated in palladium(0)-catalysed asymmetric C-H functionalizations, used for the synthesis of valuable p-lactams. The evaluation of the different TADDOL phosphoramidites revealed that the... 

In 2014, Liihr and Borner [52] investigated the hydrolysis stability of four phos-phoramidites based on lactam rings (Figure 2.42). The phosphoramidite with the smallest ring was by far the most stable. Remarkably, it also exhibited the highest activity in the rhodium-catalyzed hydroformylation of methyl oleate. 

Recently, Liihr and Borner [25] developed a new type of phosphoramidite for the same transformation (Scheme 6.81, upper part). Superior regio- and chemos-electivities were achieved with a ligand based on the four-membered lactam ring. 

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