Titanium tetrachloride and chiral aliphatic alcohol as a new Lewis acid assisted chiral Brønsted acid for the enantioselective protonation of silyl enol ether

Synlett

Volumn , Issue 1, 2006, Pages 150-152

  Nakashima, Daisuke ^a   Yamamoto, Hisashi ^a  

^a UNIVERSITY OF CHICAGO   (United States)

Author keywords

Alcohols; Asymmetric synthesis; Protonations; Titanium

Indexed keywords

ACID; ALKANOL; BRONSTED ACID; LEWIS ACID; SILANE DERIVATIVE; SILYL ENOL ETHER DERIVATIVE; TITANIUM TETRACHLORIDE; UNCLASSIFIED DRUG;

ARTICLE; ASYMMETRIC SYNTHESIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; ENANTIOSELECTIVITY; PROTON TRANSPORT; REACTION ANALYSIS;

EID: 30544443987     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2005-922782     Document Type: Article

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15. When the preparation temperature was higher than -20 °C, a small amount of 2-chloro-2-phenylethanol was observed.
16. The concentration of the reaction also affects the enantioselectivity [40% ee (R) in Scheme 2, 34% ee (R) in Scheme 3 (preparation conditions: -78 °C, 1 h)].
17. 2O) provided 2-phenylcyclohexanone in quantitative yield. The ee values were determined by analytical HPLC (OD-H, hexane-i-PrOH, 99.5:0.5).
18. 4 was prepared at 0 0C for 15 min.
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