Photoredox-Catalyzed Intramolecular Aminodifluoromethylation of Unactivated Alkenes
作者:Zuxiao Zhang、Xiaojun Tang、Charles S. Thomoson、William R. Dolbier
DOI:10.1021/acs.orglett.5b01616
日期:2015.7.17
A photoredox catalyzed aminodifluoromethylation of unactivated alkenes has been developed in which HCF2SO2Cl is used as the HCF2 radical source. Sulfonamides were active nucleophiles in the final step of a tandem addition/oxidation/cyclization process to form pyrrolidines, and esters were found to cyclize to form lactones. Thus, a variety of pyrrolidines and lactones were obtained in moderate to excellent
已经开发出未活化的烯烃的光氧化还原催化的氨基二氟甲基化,其中HCF 2 SO 2 Cl用作HCF 2自由基源。在串联加成/氧化/环化过程的最后步骤中,磺酰胺是活性亲核试剂,以形成吡咯烷,发现酯可环化以形成内酯。因此,以中等至优异的产率获得了各种吡咯烷和内酯。为了使环化反应有效,铜催化剂(Cu(dap)2 Cl)和碳酸银的组合对于抑制竞争的氯二氟烷基化过程至关重要。
Palladium-Catalyzed Intramolecular Aminoacetoxylation of Unactivated Alkenes with Hydrogen Peroxide as Oxidant
作者:Haitao Zhu、Pinhong Chen、Guosheng Liu
DOI:10.1021/acs.orglett.5b00373
日期:2015.3.20
A palladium-catalyzed intramolecular aminoacetoxylation of unactivated alkenes was developed in which H2O2 was used as the sole oxidant. A variety of 3-acetoxylated piperidines were obtained in good yields with good to excellent regio- and diastereoselectivities. Mechanistic study revealed that the addition of di(2-pyridyl) ketone (dpk) ligand was crucial to promote the oxidative cleavage of the C–Pd(II)
开发了钯催化的未活化烯烃的分子内氨基乙酰氧基化反应,其中H 2 O 2被用作唯一的氧化剂。以良好的产率获得了各种3-乙酰氧基化的哌啶,具有良好或优异的区域和非对映选择性。机理研究表明,添加二(2-吡啶基)酮(dpk)配体对于促进H 2 O 2氧化C-Pd(II)键产生C-OAc键至关重要。
Copper Catalyzed Enantioselective Intramolecular Aminooxygenation of Alkenes
作者:Peter H. Fuller、Jin-Woo Kim、Sherry R. Chemler
DOI:10.1021/ja806585m
日期:2008.12.31
methyleneoxy-functionalized dihydroindolines and pyrrolidines. Tetramethylaminopyridyl radical (TEMPO) serves as both the source of the oxygen and the stoichiometric oxidant. These reactions are catalyzed by copper(II) triflate, complexed with (4S,5R)-Bis-Phbox. The unprotected aminoalcohols can be obtained by sequential dissolving metal reductions of the N-S and O-N bonds.
本文报道了铜催化的烯烃的对映选择性分子内氨基氧化。这是对映选择性分子内烯烃氨基氧化过程的第一份报告。N-Arylsulfonyl-2-allylanilines 和 4-pentenylarylsulfonamides 以高产率和良好的对映选择性环化,提供新的手性亚甲氧基官能化二氢二氢吲哚和吡咯烷。四甲基氨基吡啶基(TEMPO)既是氧源又是化学计量氧化剂。这些反应由与 (4S,5R)-Bis-Phbox 络合的三氟甲磺酸铜 (II) 催化。未保护的氨基醇可以通过连续溶解 NS 和 ON 键的金属还原来获得。
Preparation of selenofunctionalized heterocycles via iodosobenzene-mediated intramolecular selenocyclizations of olefins with diselenides
An intramolecular selenocyclizations of olefins mediated by a commercially available hypervalent iodine(III) reagent, PhIO, was developed. This method provided access to a wide range of selenenylated heterocycles under ambient conditions. The striking advantages of this protocol over all previous methods include mild reaction conditions, easy operation, good yields, high levels of functional group
Highly Selective Palladium-Catalyzed Intramolecular Aminonitroxylation of Alkenes
作者:Guosheng Liu、Shujun Chen、Tao Wu、Xingliang Zhen
DOI:10.1055/s-0030-1259701
日期:2011.4
A palladium-catalyzedintramolecular oxidative aminonitroxylationof unactivated alkenes, in which AgNO 3 functioned as amild nitrate reagent in the presence of PhI(OAc) 2 , hasbeen developed. Mechanistic studies suggest that this selectiveaminonitroxylation reaction likely resulted from a new oxidant PhI(ONO 2 ) 2 generatedin situ from AgNO 3 and PhI(OAc) 2 .