Enantioface-differentiating (asymmetric) addition of alkyllithium and dialkylmagnesium to aldehydes by using (2S,2'S)-2-hydroxymethyl-1-[(1-alkylpyrrolidin-2-yl)methyl]pyrrolidines as chiral ligands

Synthesis of new chiral cis‐3‐hydroxyazetidines and their application in diethylzinc addition to aldehydes

“…[1][2][3][4] Among them, the enantioselective addition of organozinc to carbonyl compounds is of particular importance in organic synthesis, because the products, chiral alcohols, represent valuable structural units found in many natural products and they are readily functionalized. 5 Since the pioneering work of Oguni in 1984, 6 there has been extensive research into the diethylzinc addition to benzaldehyde, and it is now regarded as one of the benchmark reactions for understanding the catalytic potential of new ligands. Although a variety of ligands, such as chiral amino alcohols, amino thiols, amino disulfides, amino diselenides, diamines, or diols have been studied, [7][8][9][10][11] the development of new ligands for asymmetric addition of diethylzinc to aldehydes is a desirable goal.…”

Catalytic asymmetric alkylation of ketones using organometallic reagents

“…To overcome the lower reactivity of ketones, the use of highly reactive organometallic compounds such as Grignard and organolithium reagents has been explored [11][12][13][14][15]. However, these reactive organometallics are intrinsically nucleophilic and can add to carbonyl compounds without the aid of a catalyst, resulting in a racemic background reaction.…”

Asymmetric Amplification and Autocatalysis

“…The coordination of nitrogen and oxygen atoms to the zinc atom of dialkylzinc accelerates the nucleophilic attack of alkyl group to a suitable electrophile. The formation of the complex between dialkylzinc and amino alcohol enables the C -C bond -forming reaction [6] . During our continuing study on the enantioselective addition of dialkylzincs to nitrogen -containing aldehydes, we found in 1990, for the fi rst time, that chiral 3 -pyridyl alkanol 25 acts as an asymmetric autocatalyst in the addition of diisopropylzinc ( i -Pr 2 Zn) to pyridine -3 -carbaldehyde 24 (Scheme 12.30 ) [51] .…”

“…The addition reaction of diethylzinc to benzaldehyde was accelerated by an amino alcohol [6] , and then chiral amino alcohols were proved to be effi cient chiral catalysts for asymmetric alkylation by using dialkylzinc reagents [7] . Oguni reported the positive NLE in alkylation of benzaldehyde using β -amino alcohol 1 with moderate ee as a chiral base catalyst (Scheme 12.4 ) [8a] .…”