615585-08-5Relevant academic research and scientific papers
Chiral primary-tertiary diamine-bronsted acid salt catalyzed syn-selective cross-aldol reaction of aldehydes
Li, Jiuyuan,Fu, Niankai,Li, Xin,Luo, Sanzhong,Cheng, Jin-Pei
experimental part, p. 4501 - 4507 (2010/10/04)
(Figure presented) Highly syn-selective cross-aldol reaction of aldehydes has remained a challenging subject in the field of aminocatalysis. To achieve this end, chiral primary amines have been explored and the primary-tertiary diamine-Bronsted acid salts are found to promote the cross-aldol reactions of aldehydes with high activity and syn selectivity. Among various vicinal diamines screened, l-phenylalanine derived 2a/TfOH conjugate is identified as the optimal catalyst, showing good catalytic activity (up to 97% yield) and high syn selectivities (syn/anti up to 24:1, 87% ee). The current catalysis works selectively with small aliphatic aldehydes donors such as propionaldehyde and isobutyraldehyde, but not with aliphatic aldehydes bearing larger β-substitute (>Me). In addition, the use of 2a/TfOH conjugate has also enabled the first syn-selective cross-aldol reactions of glycoaldehyde donors.
N-tert-Butylbenzenesulfenamide-catalyzed oxidation of alcohols to the corresponding carbonyl compounds with N-chlorosuccinimide
Matsuo, Jun-Ichi,Iida, Daisuke,Yamanaka, Hiroyuki,Mukaiyama, Teruaki
, p. 6739 - 6750 (2007/10/03)
N-tert-Butylbenzenesulfenamide (1)-catalyzed oxidation of various primary and secondary alcohols to the corresponding aldehydes and ketones was efficiently carried out by using N-chlorosuccinimide (NCS) in the coexistence of potassium carbonate and molecular sieves 4? at easy-to-control temperatures ranging from 0°C to room temperature. The present catalytic oxidation was performed without giving any damage to the functional groups in alcohols, and was particularly effective in the oxidation of alcohols that formed labile aldehydes because of its mild reaction conditions. Further, selective oxidation of primary hydroxy groups took place in 1-catalyzed oxidation of several diols. Mechanistic investigation suggested that the chlorination of the sulfenamide 1 by NCS led to the formation of a key species, N-tert-butylbenzenesulfinimidoyl chloride (2), which in turn oxidized alcohols in the presence of potassium carbonate to afford carbonyl products by accompanying regeneration of the catalyst 1.
