2-Substituted N,N-diethyl or N,N-diisopropyl 1-naphthamides exist as stable atropisomers. When the 2-substituent is a 1-hydroxyalkyl group, the atropisomers are separable diastereoisomers. Synthesis of these compounds by the addition of aldehydes to ortholithiated N,N-dialkyl 1-naphthamides proceeds with moderate to good diastereoselectivity in favour of the aR*S* (syn) diastereoisomer.
Atroposelectivity in the reactions of ortholithiated aromatic tertiary amides with aldehydes
The products of the addition of ortholithiated
N,N-dialkylnaphthamides to aldehydes are pairs of
stable, diastereoisomeric atropisomers, formed with selectivities of up
to 90∶10 in favour of the syn-atropisomer.
Complex induced proximity effect enhancement in α-silyl carbanion generation. A general conversion of 2-silyl benzamides into 2-fluorosilylacetophenones
作者:Paul A. Brough、Stephen Fisher、Baoping Zhao、Ryan C. Thomas、Victor Snieckus
DOI:10.1016/0040-4039(96)00446-7
日期:1996.4
LDA treatment of 2-silylated benzamides 1 affords 2-fluorosilylated acetophenones 3 in a general process likely driven by CIPE-facilitated α-silylcarbanion formation and rearrangement (Scheme 3); oxidation (H2O2) of the products gives 2-hydroxyacetophenones and catechols (Scheme 4).
LDA处理2-甲硅烷基化的苯甲酰胺1在一般过程中可能由CIPE促进的α-甲硅烷基碳负离子的形成和重排驱动生成2-氟甲硅烷基化的苯乙酮3 (方案3);产物的氧化(H 2 O 2)得到2-羟基苯乙酮和儿茶酚(方案4)。