Chiral toluene-2,α-sultam auxiliaries: Asymmetric diels-alder reactions of N-enoyl derivatives
作者:Wolfgang Oppolzer、Martin Wills、Martha J. Kelly、Marcel Signer、Julian Blagg
DOI:10.1016/s0040-4039(00)97793-1
日期:1990.1
Asymmetric, RmAlCln mediated Diels-Alderreactions of 1,3-dienes to N-enoyl derivatives and of (R)-methyl-, (R,S)-t-butyl-, α,α-dimethylbenzyl-, benzyl and (S)-methyl-toluene-2,α-sultams as well as to N-enoyl derivatives of (R)-2,3-dihydro-3-methylisoindolinone are described.
Highly Enantioselective Pd-Catalyzed Asymmetric Hydrogenation of Activated Imines
作者:You-Qing Wang、Sheng-Mei Lu、Yong-Gui Zhou
DOI:10.1021/jo0700878
日期:2007.5.1
complexes are highly effective catalysts for asymmetrichydrogenation of activated imines in trifluoroethanol. The asymmetrichydrogenation of N-diphenylphosphinyl ketimines 3 with Pd(CF3CO2)/(S)-SegPhos indicated 87−99% ee, and N-tosylimines 5 could gave 88−97% ee with Pd(CF3CO2)/(S)-SynPhos as a catalyst. CyclicN-sulfonylimines 7 and 11 were hydrogenated to afford the useful chiral sultam derivatives in
Pd /双膦配合物是用于活化的亚胺在三氟乙醇中不对称氢化的高效催化剂。Pd(CF 3 CO 2)/(S)-SegPhos对N-二苯基亚膦酰基酮亚胺3的不对称氢化表明ee为87-99%,N- tosylimines 5与Pd(CF 3 CO 2)可以得到88-97%ee /(S)-SynPhos作为催化剂。环状N-磺酰亚胺7和11 进行氢化,以79-93%ee的比重得到有用的手性舒马坦衍生物,这是重要的有机合成中间体和农业和医药制剂的结构单元。
Multiple Dendritic Catalysts for Asymmetric Transfer Hydrogenation
作者:Ying-Chun Chen、Tong-Fei Wu、Jin-Gen Deng、Hui Liu、Xin Cui、Jin Zhu、Yao-Zhong Jiang、Michael C. K. Choi、Albert S. C. Chan
DOI:10.1021/jo0257795
日期:2002.7.1
and were well-characterized by NMR and MS techniques. Their ruthenium complexes prepared in situ had good solubility in the reaction medium (azeotrope of formic acid and triethylamine) and demonstrated high catalytic activity and enantioselectivity comparable to monomeric catalysts in the asymmetric transfer hydrogenation of ketones and imines. Quantitative yields and for some cases a slightly higher
Reversal of reactivity: A chemoselective direct asymmetricMichaeladdition of cyclic N‐sulfonylimines to α,β‐unsaturated aldehydes has been developed by employing chiral iminium catalysis. A tandem base‐catalyzed tautomerization of the imine group/hemiaminal formation/dehydroxylation process of the Michael adducts efficiently affords valuable tricyclic piperidine derivatives in moderate to excellent
Rhodium-Catalyzed Asymmetric Arylation of Cyclic <i>N</i>-Sulfonyl Aryl Alkyl Ketimines: Efficient Access to Highly Enantioenriched α-Tertiary Amines
作者:Tao Jiang、Zheng Wang、Ming-Hua Xu
DOI:10.1021/ol503537w
日期:2015.2.6
A simple catalyst system of Rh(I)/sulfur-olefin with exceptional catalytic performance has been developed for the highly enantioselective arylation of cyclic N-sulfonyl aryl alkyl ketimines with arylboroxines/arylboronic acids. Optically active α-arylalkyl-substituted benzosultams and benzosulfamidates which are generally difficult to obtain were easily prepared with excellent stereocontrol (up to