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。
Cobalt‐Catalyzed Transfer Hydrogenation of α‐Ketoesters and
<i>N</i>
‐Cyclicsulfonylimides Using H
<sub>2</sub>
O as Hydrogen Source
作者:Yang Gao、Xuexin Zhang、Ronibala Devi Laishram、Jingchao Chen、Kangkui Li、Keyang Zhang、Guangzhi Zeng、Baomin Fan
DOI:10.1002/adsc.201900636
日期:2019.9.3
A Co‐catalyzed effective transferhydrogenation of various α‐ketoesters and N‐cyclicsulfonylimides by safe and environmentally benign H2O as hydrogensource is described. The reaction used easily available and easy to handle zinc metal as a reductant. Interestingly, the catalytic system does not require ligand for reduction of N‐cyclicsulfonylimides.
Energy-, time-, and labor-saving synthesis of α-ketiminophosphonates: machine-learning-assisted simultaneous multiparameter screening for electrochemical oxidation
作者:Masaru Kondo、Akimasa Sugizaki、Md. Imrul Khalid、H. D. P. Wathsala、Kazunori Ishikawa、Satoshi Hara、Takayuki Takaai、Takashi Washio、Shinobu Takizawa、Hiroaki Sasai
DOI:10.1039/d1gc01583d
日期:——
electrochemical oxidation of α-amino phosphonates with the utilization of machine-learning-assisted simultaneous multiparameter screening. After brief experimental screening, the Bayesian optimization with the experimental data (up to 12 entries) could rapidly predict the optimal conditions for the synthesis of α-ketiminophosphonates and sulfonyl ketimines with aryl and alkyl groups. The obtained α-ketiminophosphonates
olefinic stereo-, and diastereoselective addition to aldehydes to give virtually single allyl alcohols. Alternatively, inter- or intramolecular coupling reaction between N-(1-alkynyl)sulfonamides and another acetylene or olefin with the above titanium alkoxide reagent generated the corresponding titanacycles, hydrolysis of which furnished stereo-defined (sulfonylamino)dienes or cyclic compounds.
A novel palladium-catalyzedintramolecular reductive amination of ketones with the low nucleophilic sulfonamides has been developed in the presence of Bronsted acid, providing a wide range of chiral [gamma]-, [small delta]-,...