Syntheses of racemic diamino-dideoxy-lyxopyranose derivatives using acylnitroso dienophiles (1).

Enantioselective Nitroso‐Diels–Alder Reaction and Its Application for the Synthesis of (−)‐Peracetylated Conduramine A‐1

“…Reactions were performed in CH 2 Cl 2 at low temperature by using [CuPF 6 A C H T U N G T R E N N U N G (MeCN) 4 ] (10 mol %) as a catalyst precursor in the presence of different chiral phosphine ligands. EnantioAbstract: Cu I -catalyzed enantioselective nitroso-Diels-Alder reactions (NDA reactions) of 2-nitrosopyridine with various dienes are presented.…”

“…EnantioAbstract: Cu I -catalyzed enantioselective nitroso-Diels-Alder reactions (NDA reactions) of 2-nitrosopyridine with various dienes are presented. The [CuPF 6 A C H T U N G T R E N N U N G (MeCN) 4 ]/Walphos-CF 3 catalyst system is best suited to catalyze the NDA reaction of various dienes by using 2-nitrosopyridine as a dienophile. In most of the cases studied, cycloadducts are obtained in quantitative yield with very good to excellent enantioselectivities.…”

“…Moderate enantioselectivities were obtained with (S)-Binap (99 %, 55 % ee) and (R)-Solphos (99 %, 11 % ee) as ligands (entries 5, 6). As a result of the initial ligand screening, all of the following cycloadditions were performed in CH 2 Cl 2 by using the diene (1.1 equiv) and 2-nitrosopyridine in the presence of 10 mol % [CuPF 6 A C H T U N G T R E N N U N G (MeCN) 4 ]/Walphos-CF 3 . For most of the reactions conducted, the product was formed with excellent yield.…”

“…Importantly, adduct 18 can readily be transformed to diaminodideoxylyxopyranose. [6] To understand the stereoselectivity of the nitroso-DA reaction with substituted cyclohexa-1,3-dienes the structure of the Cu I /Walphos-CF 3 catalyst complexed with 2-nitrosopyridine was studied theoretically by using DFT calculations (Figure 2). [7] As can be seen from the minimized structure, the cyclohexadiene can approach the Cu-complexed nitroso compound only from the north/east direction.…”

“…Reductive N À O bond cleavage in 9 with Mo(CO) 6 /NaBH 4 [10] and O-silylation afforded protected amino alcohol 19 in a good yield (91 %). Carbamoylation of [5c]…”