ABSTRACT
An inexpensive Fe(III) SALPN catalyst for MHAT reactions such as reductions of α,ß-unsaturated carbonyl compounds and olefin cross couplings is reported. The majority of these reactions proceeded in good yields and high stereoselectivities with low catalyst loadings at room temperature.
ABSTRACT
The acyloin natural products are a family of bioactive compounds isolated from fungi and myxobacteria. The total synthesis of 7 members of the acyloin family was achieved via a HWE reaction followed by Mukaiyama-Isayama hydration, using novel Co(II) and Co(III) Schiff base SALPN complexes as catalysts for the key enone hydration step. Furthermore, we have shown that a mild acyloin rearrangement is possible under Mukaiyama hydration conditions, which was crucial in the success of this approach.
Subject(s)
Biological Products , Catalysis , Fatty Alcohols , Schiff BasesABSTRACT
This review details the isolation, biosynthesis, biological activity and synthesis of spiroacetals from the myxobacterium Sorangium cellulosum. The strategies utilised to access the challenging structures and stereochemistry of these natural products are highlighted.
Subject(s)
Acetals/metabolism , Biological Products/metabolism , Spiro Compounds/metabolism , Acetals/chemistry , Biological Products/chemistry , Molecular Conformation , Sorangium/chemistry , Sorangium/metabolism , Spiro Compounds/chemistry , StereoisomerismABSTRACT
Two cis-ß-MnIIISALPN catalysts were synthesised and tested in the Mukaiyama-Isayama hydration of α,ß-unsaturated esters. The MnIIIEtOSALPN(acac) complex 7 is the most active and catalyses hydration with little or no detectable undesired alkene reduction. This catalyst is superior for alkene hydration compared to the originally reported Mn(dpm)3 catalyst.
