Enantioselective Radical Construction of 5-Membered Cyclic Sulfonamides by Metalloradical C–H Amination
作者:Yang Hu、Kai Lang、Chaoqun Li、Joseph B. Gill、Isaac Kim、Hongjian Lu、Kimberly B. Fields、McKenzie Marshall、Qigan Cheng、Xin Cui、Lukasz Wojtas、X. Peter Zhang
DOI:10.1021/jacs.9b08894
日期:2019.11.13
azides can be effectively activated by the cobalt(II) complexes of D2-symmetric chiral amidoporphyrins for enantioselective radical 1,5-C-H amination to stereoselectively construct 5-membered cyclic sulfonamides. In addition to C-H bonds with varied electronic properties, the Co(II)-basedmetalloradical system features chemoselectiveamination of allylic C-H bonds and is compatible with heteroaryl groups
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。
Complementing Pyridine‐2,6‐bis(oxazoline) with Cyclometalated N‐Heterocyclic Carbene for Asymmetric Ruthenium Catalysis
6‐bis(oxazoline) (pybox) ligands for asymmetric transition metal catalysis is introduced by adding a bidentate ligand to modulate the electronic properties and asymmetric induction. Specifically, a ruthenium(II) pybox fragment is combined with a cyclometalated N‐heterocyclic carbene (NHC) ligand to generate catalysts for enantioselective transition metal nitrenoid chemistry, including ring contraction
通过添加双齿配体来调节电子性质和不对称诱导,提出了扩大手性吡啶-2,6-双(恶唑啉)(pybox)配体在不对称过渡金属催化中的应用的策略。具体来说,钌 (II) pybox 片段与环金属化 N-杂环卡宾 (NHC) 配体结合,生成用于对映选择性过渡金属氮烯化学的催化剂,包括环收缩为手性 2H-氮丙啶(2000 TON 时高达 97% ee)和对映选择性 C(sp 3 )−H 胺化(50 TON 时高达 97 % ee)。
Asymmetric Hydrogenation of Cyclic N-Sulfonylimines with Phosphine-Free Chiral Cationic Ru-MsDPEN Catalysts
作者:Fei Chen、Zhiwei Li、Yanmei He、Qinghua Fan
DOI:10.1002/cjoc.201090260
日期:2010.9
Phosphine‐free chiralcationic Ru/diamine complexes are effective catalysts for the asymmetrichydrogenation of a range of cyclic N‐sulfonylimines, affording chiral sultam derivatives with good to excellent enantioselectivity (up to 94% ee).
Highly Enantioselective Synthesis of Sultams via Pd-Catalyzed Hydrogenation
作者:Chang-Bin Yu、Da-Wei Wang、Yong-Gui Zhou
DOI:10.1021/jo900790k
日期:2009.8.7
Using pd(cf3co2)2/(S,S)-f-Binaphane as the catalyst, an efficient enantioselective synthesis of sultams was developed via asymmetric hydrogenation of the corresponding cyclic imines with high enantioselectivities. The hydrogenation products can be conveniently transformed to chiral homoallylic amines without loss of enantioselectivity.
以pd(cf 3 co 2)2 /(S,S)-f-Binaphane为催化剂,通过高对映选择性的相应环状亚胺的不对称加氢反应,开发了有效的对映异构体。氢化产物可以方便地转化为手性均烯丙基胺,而不会损失对映选择性。