Structure influence of chiral 1,1′-biscarboline-N,N′-dioxide on the enantioselective allylation of aldehydes with allyltrichlorosilanes
作者:Bing Bai、Hua-Jie Zhu、Wei Pan
DOI:10.1016/j.tet.2012.06.042
日期:2012.8
A series of new axially chiral 1,1′-biscarboline-N,N′-dioxide Lewis base organocatalysts were examined in the asymmetricallylation of aldehydes with allyltrichlorosilane. The chiral catalysts (R)-1a–e bearing ester groups in 3,3′ position provided good yields of the homoallyl alcohols with excellent enantioselectivities up to 99% for a broad substrate scope that covers aliphatic, aromatic, heteroaromatic
Chiral Biscarboline N,N′-Dioxide Derivatives: Highly Enantioselective Addition of Allyltrichlorosilane to Aldehydes
作者:Bing Bai、Lan Shen、Jie Ren、Hua Jie Zhu
DOI:10.1002/adsc.201100592
日期:2012.2
The allylation of aromatic and aliphatic aldehydes with allyltrichlorosilanes has been catalyzed with a new Lewis base organocatalyst, 1,1′-biscarboline N,N′-dioxide with high enantioselectivities of up to 99% for 4-methoxybenzaldehyde and 97% ee for cycloformaldehyde, respectively. In total, 13 heteroaryl and aliphatic aldehydes were tested.
Two new chiral diphenylphosphine dioxides bearing an original bis(triazolyl) backbone were prepared through a two‐step sequence. The key reactioninvolves a copper‐catalyzed [3+2] cycloaddition/dimerization reaction leading to the formation of five bonds in one chemical step with 100 % atom efficiency. Interestingly, these ligands exhibited good to excellent catalytic activities as chiral Lewis base
of C10-BridgePHOS oxides possessing different substituted groups on the diphenyl phosphine system were synthesized and tested as organocatalysts in the allylation of aldehydes with allyltrichlorosilane, providing chiral homoallylic alcohols. These types of organocatalysts showed high catalytic activity and only 2 mol% catalyst loading was required to induce short reaction times. Under optimal reaction
Axially chiral
<i>N,N′‐</i>
dioxides ethers for catalysis in enantioselective allylation of aldehydes
作者:Shijie Wu、Yongfei Xing、Jie Wang、Xingchen Guo、Huajie Zhu、Wan Li
DOI:10.1002/chir.23122
日期:2019.11
A series of axially chiral ethers synthesized from biscarboline N,N′‐dioxides, (S)‐1a to (S)‐1n, was investigated in enantioselectivity addition reactions of allyltrichlorosilane with a series of substituted aldehydes, including bulky substituted aldehydes. High enantioselectivities (up to 96%ee) were achieved using the catalyst (S)‐1k at 1 mol % loading.