cyclohexyl groups on the phosphorous donors were used, high reactivity could be
achieved. If isopropyl groups were used, slightly lower yields were detected,
whereas phenyl groups performed moderately. Under optimized conditions, a catalyst loading as low as 0.5 mol% with reduced equivalent of esters and amides and
base and lower reaction temperatures could be achieved in comparison to other
procedures [80].
The group of Sortais reported on the methylation of benzylic ester using methanol
as alkylation agent, employing Mn3 [78]. An overview of esters and amide
functionalization is given in Scheme 46.
Scheme 46 Alkylation of esters and amides catalyzed by Mn(I) catalysts
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S. Weber and K. Kirchner