Organocatalytic Vinyl and Friedel−Crafts Alkylations with Trifluoroborate Salts
作者:Sandra Lee、David W. C. MacMillan
DOI:10.1021/ja0767480
日期:2007.12.1
pathway. Boronic acids can also be employed as viable π-nucleophiles for these asymmetric conjugate additions provided that in situ activation to the corresponding boronate species is accomplished. While BF3K salts are routinely employed in transition metal catalysis, to our knowledge, this is the first use of this activation group for organic catalysis or Friedel−Crafts alkylations.
CuH-Catalyzed Asymmetric Reduction of α,β-Unsaturated Carboxylic Acids to β-Chiral Aldehydes
作者:Yujing Zhou、Jeffrey S. Bandar、Richard Y. Liu、Stephen L. Buchwald
DOI:10.1021/jacs.7b12260
日期:2018.1.17
The copper hydride (CuH)-catalyzed enantioselective reduction of α,β-unsaturatedcarboxylicacids to saturated aldehydes is reported. This protocol provides a new method to access a variety of β-chiral aldehydes in good yields, with high levels of enantioselectivity and broad functional group tolerance. A reaction pathway involving a ketene intermediate is proposed based on preliminary mechanistic