474-45-3Relevant articles and documents
Predictable Selectivity in Remote C?H Oxidation of Steroids: Analysis of Substrate Binding Mode
Olivo, Giorgio,Capocasa, Giorgio,Ticconi, Barbara,Lanzalunga, Osvaldo,Di Stefano, Stefano,Costas, Miquel
, p. 12703 - 12708 (2020/06/02)
Predictability is a key requirement to encompass late-stage C?H functionalization in synthetic routes. However, prediction (and control) of reaction selectivity is usually challenging, especially for complex substrate structures and elusive transformations such as remote C(sp3)?H oxidation, as it requires distinguishing a specific C?H bond from many others with similar reactivity. Developed here is a strategy for predictable, remote C?H oxidation that entails substrate binding to a supramolecular Mn or Fe catalyst followed by elucidation of the conformation of the host-guest adduct by NMR analysis. These analyses indicate which remote C?H bonds are suitably oriented for the oxidation before carrying out the reaction, enabling prediction of site selectivity. This strategy was applied to late-stage C(sp3)?H oxidation of amino-steroids at C15 (or C16) positions, with a selectivity tunable by modification of catalyst chirality and metal.
A novel scalable and stereospecific synthesis of 3α- and 3β-amino-5α-androstan-17-ones and 3α- and 3β-amino- 5α-pregnan-20-ones
Hitchin, James R.,Hamilton, Niall M.,Jordan, Allan M.,Lyons, Amanda J.,Ogilvie, Donald J.
, p. 2868 - 2872 (2012/07/27)
A novel scalable stereoselective synthesis of 3α- and 3β-amino-5α-androstan-17-ones and 3α- and 3β-amino- 5α-pregnan-20-ones has been developed using phthalimide based Mitsunobu chemistry. In all four cases, the products were isolated as single diastereoisomers in high chemical yield and purity without the need for chromatography at any stage in their syntheses.
Steroid alkaloids. Holaphyllamine and holamine, alkaloids from Holarrhena floribunda (G. Don) Dur. and Schinz.
JANOT,CAVE,GOUTAREL
, p. 559 - 561 (2007/10/14)
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