A new method for CuF-catalyzed alkenylation and phenylation of aldehydes and an activated ketone using air- and moisture-stable alkenylsilanes and phenylsilane as a nucleophile is described. This methodology was extended to highly enantioselective catalytic alkenylation and phenylation using DTBM-SEGPHOS as a chiral ligand. Substrate generality is broad, and an alkenylsilane with a long alkyl chain
A highly enantioselective synthesis of chiral allylic alcohols by asymmetric addition of novel mixed reagents of trialkenylbismuthines/dialkylzincs to aldehydes
作者:Itaru Sato、Noriaki Asakura、Taizo Iwashita
DOI:10.1016/j.tetasy.2007.10.031
日期:2007.11
A novel mixture of reagents of trialkenylbismuthines/dialkylzincs was developed and applied toward the synthesis of chiral allylic alcohols. The chiral β-amino alcohols catalyzed addition of the mixed reagents of trialkenylbismuthines/dialkylzincs to aldehydes gave enantiomerically enriched allylic alcohols with up to 97% ee.
Enantioselective vinylation of aldehydes with the vinyl Grignard reagent catalyzed by magnesium complex of chiral BINOLs
作者:Pei Wang、Guo-Rong Ma、Sheng-Li Yu、Chao-Shan Da
DOI:10.1002/chir.23038
日期:2019.1
Enantioselective vinylation of aldehydes via direct catalytic asymmetric Grignard reaction of aldehdyes and the vinyl Grinard reagent is a long‐standing challenge. This work demonstrated that the magnesium (S)‐3,3′‐dimethyl BINOLate enantioselectivelycatalyze the direct vinylation of aldehydes with the deactivated vinylmagnesium bromide by bis(2‐[N,N′‐dimethylamino]ethyl) ether (BDMAEE) in the addition
2,6-Bis(2-alkylphenyl)-3,5-dimethylphenol as a New Chiral Phenol with <i>C</i><sub>2</sub>-Symmetry. Application to the Asymmetric Alkylation of Aldehydes
Enantioselective esterifications of unsaturated alcohols mediated by a lipase prepared from Pseudomonas sp
作者:Kevin Burgess、Lee D. Jennings
DOI:10.1021/ja00016a032
日期:1991.7
Competition experiments and measurements of enantioselectivities were used to develop a simple active-site model (Figure 1) for resolutions of beta-hydroxy-alpha-methylene carbonyl compounds III via acyl transfers mediated by lipase from Pseudomonas sp. (AK). Further experiments were used to test and refine this model with respect to resolutions of allylic, propargylic, homopropargylic, and other alcohols (Tables I-IV, respectively). The model proved extremely reliable for predicting the sense of the asymmetric induction, and the combined data collected in this paper give an indication of what structural features of the substrates can be correlated with high enantioselectivities in these resolutions. Furthermore, the results account for the conspicuous reversal of enantioselectivity previously observed in resolutions of gamma-hydroxy-alpha,beta-unsaturated esters 35. Kinetic resolutions of two substrates (allenol 14 and dienol 9) via asymmetric epoxidations were performed for comparison with the methodology presented in this paper.