Synfacts 2020; 16(11): 1327
DOI: 10.1055/s-0040-1706337
Metals in Synthesis

Titanium-Catalyzed Asymmetric Pauson–Khand Type Reaction

Contributor(s):
Mark Lautens
,
Randy Sanichar
Hicks FA, Buchwald SL. * Massachusetts Institute of Technology, Cambridge, USA
Highly Enantioselective Catalytic Pauson–Khand Type Formation of Bicyclic Cyclopentenones.

J. Am. Chem. Soc. 1996;
118: 11688-11689
DOI: 10.1021/ja9630452.
 

Significance

Hicks and Buchwald reported an asymmetric titanium-catalyzed Pauson–Khand type reaction to access bicyclic cyclopentenones in excellent yields and enantioselectivity. In addition to good to excellent ee values, the reaction also tolerates 1,1-disubstituted olefins amongst its wide substrate scope; a weakness in earlier Pauson–Khand systems.


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Comment

The active catalyst is generated in situ, from (S,S)-(EBTHI)TiMe2. Both temperature of the reaction and the pressure of CO impacted the yield; temperatures lower than 90 °C or pressures above and below 14 psig were observed to result in diminished conversions.


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Review

S. E. Gibson (née Thomas), A. Stevenazzi Angew. Chem. Int. Ed. 2003, 42, 1800–1810.


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Publication History

Publication Date:
20 October 2020 (online)

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