Enantioselective C-H Amination

Chiral Amine Synthesis Methods, Developments and Applications. Edited by Thomas C. Nugent Copyright 2010 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-32509-2 

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As shown in the previous two sections, rhodium(n) dimers are superior catalysts for metal carbene C-H insertion reactions. For nitrene C-H insertion reactions, many catalysts found to be effective for carbene transfer are also effective for these reactions. Particularly, Rh2(OAc)4 has demonstrated great effectiveness in the inter- and intramolecular nitrene C-H insertions. The exploration of enantioselective C-H amination using chiral rhodium catalysts has been reported by several groups.225,244,253-255 Hashimoto s dirhodium tetrakis[A-tetrachlorophthaloyl-(A)-/ r/-leuci-nate], Rh2(derived rhodium complex, Rh2(i -BNP)4 48,244 afforded moderate enantiomeric excess for amidation of benzylic C-H bonds with NsN=IPh. 

Scheme 12.18 Ru catalyzed enantioselective C H amination of sulfamate esters.

Scheme 12.19 Ru (I I) pybox catalyst and its application to enantioselective C H amination.

Rli2(S nap)2 is an effective catalyst for the enantioselective C H amination of the cis olefin but gives lower yield and poor enantioselectivity in the case of the corresponding trans olefin. The opposite behavior is observed with the RuBr2 pybox catalyst 43. 

Fig. 24 Enantioselective C-H amination catalyzed by the chiral lactamate complex, Rh2(S-nap)4...

Reddy RP, Davies HML. Dirhodium tetracarboxylates derived from adamantylglycine as chiral catalysts for enantioselective C-H aminations. Org Lett. 2006 8 5013-5016. 

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