Visible photocatalysis of novel oxime phosphonates: synthesis of β-aminophosphonates
作者:Yong-Hong Li、Chun-Hai Wang、Su-Qian Gao、Feng-Ming Qi、Shang-Dong Yang
DOI:10.1039/c9cc06075h
日期:——
A novel type of oxime phosphonate was synthesized and used in the intermolecular cascade radical addition reaction of alkenes to access β-aminophosphonates via visible-light-driven N-centered iminyl radical-mediated and redox-neutral selective C–P single-bond cleavage in an active phosphorus radical route. The procedure is characterized by its ability to achieve the construction of Csp3–P and Csp3–N
Enantioselective Conjunctive Cross-Coupling of Bis(alkenyl)borates: A General Synthesis of Chiral Allylboron Reagents
作者:Emma K. Edelstein、Sheila Namirembe、James P. Morken
DOI:10.1021/jacs.7b01774
日期:2017.4.12
conjunctive cross-coupling is used for the synthesis of enantioenriched allylboron reagents. This reaction employs nonsymmetric bis(alkenyl)borates as substrates and appears to occur by a mechanism that involves selective activation of the less substituted alkene followed by migration of the more substituted alkene during the course of a Pd-induced metalate rearrangement.
base-mediated hydroamination protocol, using substoichiometric amounts of a hydrosilane and potassium tert-butoxide, that operates under mild conditions at 30 °C. Many aryl- and heteroatom-substituted olefins as well as arylamines are tolerated, affording the desired products with complete regioselectivity. Preliminary mechanistic investigations reveal a non-radical pathway for hydroamination. A sequential
我们提出了一种碱介导的加氢胺化方案,使用亚化学计量的氢硅烷和叔丁醇钾,在 30°C 的温和条件下运行。可以耐受许多芳基和杂原子取代的烯烃以及芳基胺,从而提供具有完全区域选择性的所需产物。初步的机理研究揭示了加氢胺化的非自由基途径。还开发了一种顺序远程加氢胺化策略,包括初始 Fe 催化的烯烃异构化,然后是我们的碱介导的加氢胺化,以直接从末端脂肪族烯烃中获取 β-芳基胺。
Umpolung Synthesis of 1,3-Amino Alcohols: Stereoselective Addition of 2-Azaallyl Anions to Epoxides
作者:Paige E. Daniel、Alexandria E. Weber、Steven J. Malcolmson
DOI:10.1021/acs.orglett.7b01471
日期:2017.7.7
report the direct preparation of 1,3-amino alcohols that contain up to three contiguous stereogenic centers by the umpolung coupling of imines and epoxides. Nucleophilic 2-azaallyl anions, generated from imines, are stereoselectively added to epoxides to furnish 1,3-amino alcohols after hydrolysis of the product imine. Transformations afford amino alcohols with >98% site selectivity with respect to
Highly chemo- and stereoselective Fe-catalyzed alkenylation of organomanganese reagents
作者:Gérard Cahiez、Sophie Marquais
DOI:10.1016/0040-4039(96)00116-5
日期:1996.3
Organomanganese chlorides react with alkenyl iodides, bromides and chlorides in the presence of 3% Fe(acac)3. The reaction takes place under very mild conditions (THF-NMP, rt, 1h) to afford the substituted olefin in excellent yields with a high stereo- and chemoselectivity. Thus an unprotected keto alkenyl chloride selectively gives the corresponding keto olefin. From a preparative point of view, this