- Highly Enantioselective Iridium-Catalyzed Hydrogenation of Conjugated Trisubstituted Enones
-
Asymmetric hydrogenation of conjugated enones is one of the most efficient and straightforward methods to prepare optically active ketones. In this study, chiral bidentate Ir-N,P complexes were utilized to access these scaffolds for ketones bearing the stereogenic center at both the α- and β-positions. Excellent enantiomeric excesses, of up to 99%, were obtained, accompanied with good to high isolated yields. Challenging dialkyl substituted substrates, which are difficult to hydrogenate with satisfactory chiral induction, were hydrogenated in a highly enantioselective fashion.
- Peters, Bram B. C.,Jongcharoenkamol, Jira,Krajangsri, Suppachai,Andersson, Pher G.
-
supporting information
p. 242 - 246
(2021/01/13)
-
- Thermolysis of 4-Methyl-4-(1-propenyl)malonyl Peroxide: Mechanistic Limits to Chemiluminescence Efficiency
-
The preparation and thermal chemistry of 4-methyl-4-(1-propenyl)malonyl peroxide (3) is described.Thermolysis in acetonitrile at 84 deg C gives 2,4-dimethylbut-2-en-4-olide in 45percent yield and an oligomeric ester derived from an intermediate α-lactone in 55percent yield.The reaction of 3 can be catalyzed by aromatic hydrocarbons such as perylene.Under these conditions weak chemiluminescence results.The mechanism for light generation is identified as chemically initiated electron-exchange luminescence (CIEEL).Application of the CIEEL mechanism to 3 reveals an important limitation to light generation by this path.
- Porter, Judith E.,Schuster, Gary B.
-
p. 4068 - 4071
(2007/10/02)
-