In recent years, progress has been made in the field of asymmetric counteranion-directed silylium Lewis acid catalysis (silylium ACDC), using carbonyls, imines or Michael acceptors as electrophiles in nucleophilic additions and cycloadditions 22, 23, 24, 25, 26, 27, 28, 29. However, catalytic asymmetric additions of nucleophiles to silyl nitronates are unknown, even though the nitroso acetal products of such processes should be direct precursors for highly valuable products such as β 3-amino acids (Fig. The phenomenon has been described by Ioffe and co-workers in silicon Lewis-acid-catalysed reactions of mostly cyclic silyl nitronates with silylated and stannylated nucleophiles 14, 15, 16, 17, 18, 19, 20. This property makes silyl nitronates susceptible to activation by Lewis acids, in turn converting them into highly reactive electrophiles 12, 13. A key structural feature of silyl nitronates is the formally negatively charged and highly Lewis-basic oxygen atom. An amine-catalysed single-electron-transfer-based strategy has also been employed for the α-nitroalkylation of aldehydes by MacMillan and co-workers. 1a) were used by Jørgensen and co-workers in enantioselective bis(oxazoline) copper-complex-catalysed Mukaiyama–Henry reactions with α-imino esters 7 and aldehydes 8, and by Maruoka and co-workers in ammonium bifluoride phase-transfer-catalysed stereoselective Mukaiyama–Michael and Mukaiyama–Henry reactions 9, 10. Although their distinct properties offer a new reactivity paradigm for nitro compounds, there are few examples of their application in chemical synthesis. Silyl nitronates were first described by Ioffe and co-workers in 1974 2 and were subsequently thoroughly investigated by Seebach and Torssell and co-workers 3, 4, 5, 6. A remarkable reactivity difference, however, arises upon silylation of these anions: whereas a silylated enolate exhibits high nucleophilicity and reacts with various classes of electrophiles in Lewis-acid-mediated, Mukaiyama-type reactions, the silylation of a nitronate anion creates a bi-reactive species, a so-called ambiphile, which can react with both electrophiles and nucleophiles 1. Nitroalkanes, like carbonyl compounds, upon deprotonation engage in useful (catalytic) transformations with electrophiles, including Henry- and Michael-type reactions.

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