A facile enzyme assisted route to (R) - and (S)-t-butyloxirane and related β-amino alcohols - catalysts for the enantioselective addition of dialkylzinc reagents to aldehydes

1,2-Amino Alcohols and Their Heterocyclic Derivatives as Chiral Auxiliaries in Asymmetric Synthesis

“…There are a number of means to achieve this with simple alkenes, but the one with most promise is that based on the use of manganese−salen. − With unsymmetrical epoxides, the regioselectivity can be controlled through reagent choice . Nucleophilic attack tends to prefer reaction at the least hindered center with concurrent inversion, as observed with primary and secondary amines (Scheme ), − and their group I or II metal salts, ,− while group IV and V amine compounds tend to provide reaction of the nitrogen nucleophile at the more hindered center. −

16

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“…[84][85][86][87][88][89][90][91] With unsymmetrical epoxides, the regioselectivity can be controlled through reagent choice. 92 Nucleophilic attack tends to prefer reaction at the least hindered center with concurrent inversion, as observed with primary and secondary amines (Scheme 16), [93][94][95][96][97][98][99][100][101][102][103] and their group I or II metal salts, 95,[104][105][106][107] while group IV and V amine compounds tend to provide reaction of the nitrogen nucleophile at the more hindered center. [108][109][110][111][112] Azides can also be used as the nucleophilic species and a similar regiochemical trend is observed.…”