Inverted Diastereoselectivity in Asymmetric Aziridine Synthesis via Aza-Darzens Reaction of (2S)-N-Bromoacyl Camphorsultam
摘要:
[GRAGHICS]The aza-Darzens reaction of the chiral enolate derived from (2S) bromoacetyl camphor sultam (1) with certain C-3-substituted N-diphenylphosphinyl imines gives mixtures of trans- and cis-aziridines. In some cases, only trans isomers are observed. A steric repulsion between the enolate halogen atom and this C-3-substituent is invoked to rationalize these observations.
Synthesis of N-Diphenylphosphinoylimines Using the Kresze Reaction
摘要:
The synthesis of N-diphenylphosphinoylimines involving the treatment of aldehydes with PP-diphenyl N-sulfinylphosphoramidate (Ph2P(O)NSO) is described. The reagent is prepared from PP-diplienylphosphinic amide, thionyl chloride, and imidazole.
Enantioselective synthesis of diaryl aziridines using tetrahydrothiophene-based chiral sulfides as organocatalysts
作者:Meng-Ting Huang、Hsin-Yi Wu、Rong-Jie Chein
DOI:10.1039/c3cc47550f
日期:——
This work describes catalytic and asymmetricaziridinations (15 examples, 95-98% ee) of benzyl bromide and imines via the imino Corey-Chaykovsky reaction using (thiolan-2-yl)diarylmethanol benzyl ether as an organocatalyst. The catalyst and analogues thereof were prepared through an expeditious and efficient synthetic route featuring a double nucleophilic substitution and Shi epoxidation as key steps
[EN] SIMPLE ORGANIC MOLECULES AS CATALYSTS FOR PRACTICAL AND EFFICIENT ENANTIOSELECTIVE SYNTHESIS OF AMINES AND ALCOHOLS<br/>[FR] MOLÉCULES ORGANIQUES SIMPLES EN TANT QUE CATALYSEURS POUR LA SYNTHÈSE ÉNANTIOSÉLECTIVE PRATIQUE ET EFFICACE D'AMINES ET D'ALCOOLS
申请人:TRUSTEES BOSTON COLLEGE
公开号:WO2013131043A1
公开(公告)日:2013-09-06
The present invention provides organic molecules and methods thereof for reactions between organoboron reagents and double bonds, such as imines or carbonyls, to stereoselectively provide chiral products including amines and alcohols, entities useful for the preparation of biologically active molecules.
The Catalytic Asymmetric Addition of Diethylzinc toN-(Diphenylphosphinoyl) Imines Catalyzed by Cu(OTf)2-ChiralN-(Binaphthyl-2-yl)thiophosphoramide Ligands
作者:Min Shi、Chun-Jiang Wang
DOI:10.1002/adsc.200303041
日期:2003.8
Chiral N-(binaphthyl-2-yl)thiophosphoramide L7 [O,O-diethyl 2′-(ethylamino)-1,1′-binaphthyl-2-ylamidothiophosphate] prepared from the reaction of diethyl chlorothiophosphate with (R)-(+)-N-ethyl-1,1′-binaphthyl-2,2′-diamine was used as a catalytic chiral ligand in the first Cu(OTf)2-promoted catalyticasymmetricaddition of diethylzinc to N-(diphenylphosphinoyl) imines in which ~85% ee can be realized
A new family of phosphinthiourea catalysts was developed for the highly enantioselective synthesis of 2-aryl-2,5-hydropyrroles via a [3 + 2] cycloaddition of an electron-deficient allene with aryl and heteroaryl diphenylphosphinoylimines. The presence of both H(2)O and Et(3)N as additives was found to be important for achieving optimal rates. Dual activation of both nucleophile and electrophile by the bifunctional catalyst is invoked to account for the observed high reactivity and enantioselectivity.