Manganese-Catalyzed β-Alkylation of Secondary Alcohols with Primary Alcohols under Phosphine-Free Conditions
作者:Tingting Liu、Liandi Wang、Kaikai Wu、Zhengkun Yu
DOI:10.1021/acscatal.8b01960
日期:2018.8.3
secondary alcohols with primary alcohols under phosphine-free conditions. The β-alkylated secondary alcohols were obtained in moderate to good yields with water formed as the byproduct through a borrowinghydrogen pathway. β-Alkylation of cholesterols was also effectively achieved. The present protocol provides a concise atom-economical method for C–C bond formationfrom primary and secondary alcohols.
Bimetallic Pt–Sn/γ-Al 2 O 3 catalyzed β-alkylation of secondary alcohols with primary alcohols under solvent-free conditions
作者:Kaikai Wu、Wei He、Chenglin Sun、Zhengkun Yu
DOI:10.1016/j.tetlet.2016.07.037
日期:2016.9
Pt, molar ratio Pt:Sn = 1:3) was successfully utilized as the catalyst for direct β-alkylation of secondary alcohols with primary alcoholsundersolvent-freeconditions. β-Alkylated secondary alcohols were obtained in moderate to high yields with water formed as the by-product through a hydrogen borrowing pathway. The present protocol provides a concise atom-economical and environmentally benign method
at 140 °C with high yields and unprecedented turnovers. A maximum of 92% yield of the β-alkylated product at 18 400 TON was obtained in the reaction of benzyl alcohol with 1-(4-(trifluoromethyl)phenyl)ethane-1-ol in the presence of 0.005 mol % of (Ph2NNN)NiCl2(CH3CN) and 5 mol % of NaOtBu at 140 °C after 24 h. The reaction exhibits zero-order dependence of rate on catalyst concentration and first-order
我们在此报告了一系列类型为 ( R2 NNN)NiCl 2 (CH 3 CN) (R = i Pr、t Bu、Cy、Ph 和p -FC 6 H 4 )的 NNN 钳形镍配合物的合成和表征) 基于双(亚氨基)吡啶配体。在溶液中,这些配合物被发现是分别含有一个和两个钳状配体的平衡混合物。虽然我们最近报道了前者的晶体结构 R = i Pr,但我们在本研究中报告了后者的晶体结构 R = p -FC 6 H 4. 所考虑的 NNN 钳形镍配合物已成功用于在 140°C 下以高产率和前所未有的周转率完成几种仲醇与各种苄醇的催化 β-烷基化。在苯甲醇与 1-(4-(三氟甲基)苯基)乙烷-1-醇在 0.005 mol% ( Ph2 NNN)NiCl 2 (CH 3 CN) 和 5 mol % NaO tBu 在 140 °C 后 24 小时。该反应表现出速率对催化剂浓度的零级依赖性和对碱、苯甲醇和 1-苯
Phosphine-free pincer-ruthenium catalyzed biofuel production: high rates, yields and turnovers of solventless alcohol alkylation
ethanol with 3-methoxy benzyl alcohol. DFT studies were complementary to mechanisticstudies and indicate the β-hydride elimination step involving the extrusion of acetophenone to be the overall RDS. While the hydrogenation step is favored for the formation of α-alkylated ketone, the alcoholysis step is preferred for the formation of β-alkylated alcohol. The studies were extended for the upgradation of ethanol
合成了基于双(亚氨基)吡啶和2,6-双(苯并咪唑-2-基)吡啶配体的无膦钳式钌羰基配合物。在无溶剂条件下,在140°C下用苯甲醇将1-苯基乙醇与苄醇进行β-烷基化反应,(Cy2 NNN)RuCl 2(CO)(0.00025 mol%)与NaOH(2.5 mol%)的结合非常有效(约93%的产率,在12000 TO h -1时为37.2万吨。这是迄今为止基于钌的催化剂的最高报道值。轻松完成各种醇组合的β-烷基化反应,最终在19 000 TO h -1达到380000 TON1-苯基乙醇与3-甲氧基苄醇的β-烷基化反应。DFT研究是对机理研究的补充,并指出涉及苯乙酮挤出的β-氢化物消除步骤成为整个RDS。尽管有利于形成α-烷基化的酮的氢化步骤,但是对于形成β-烷基化的醇,醇解步骤是优选的。研究扩大了将乙醇升级为生物燃料的研究。在基于双(亚氨基)吡啶的钳-钌络合物中,(Cy2 NNN)RuCl 2(CO)提供了高生产率(在170
Diaminocyclopentadienone Ruthenium Complex Catalyzed Alkylation of Indoles and Ketones with Primary Alcohols
作者:Steffen Skowaisa、Edgar Haak
DOI:10.1002/ejoc.202300707
日期:——
The borrowing hydrogen approach allows the direct utilization of non-activated alcohols as alkylating agents. A readily available, air and moisture stable ruthenium complex proves to be a particularly effective hydrogen autotransfer catalyst for the alkylation of various indoles or ketones with poorly reactive alcohols.