Metal-free C–H alkylation of heteroarenes with alkyltrifluoroborates: a general protocol for 1°, 2° and 3° alkylation
作者:Jennifer K. Matsui、David N. Primer、Gary A. Molander
DOI:10.1039/c7sc00283a
日期:——
A photoredox-catalyzed C–H functionalization of heteroarenes using a variety of primary, secondary, and tertiary alkyltrifluoroborates is reported. Using Fukuzumi's organophotocatalyst and a mild oxidant, conditions amenable for functionalizing complex heteroaromatics are described, providing a valuable tool for late-stage derivatization. The reported method addresses the three major limitations of
据报道,使用各种伯,仲和叔烷基三氟硼酸酯进行光氧化还原催化的杂芳烃的CH官能化。描述了使用Fukuzumi的有机光催化剂和温和的氧化剂,适合于功能化复杂杂芳族化合物的条件,为后期衍生化提供了有价值的工具。报告的方法解决了先前报道的光氧化还原介导的Minisci反应的三个主要局限性:(1)使用超化学计量的自由基前体,(2)反复选择性,以及(3)引入昂贵的光催化剂。另外,使用了许多前所未有的复杂烷基,从而增加了Minisci化学可利用的化学空间。为了展示后期功能化中的应用程序,合成了奎宁和喜树碱类似物。最后,进行了NMR研究以提供合理的杂芳基活化作用,该活化作用允许使用单当量的自由基前体,并且还提高了区域选择性。因此,在酸催化剂和BF 3的存在下观察到1 H和13 C NMR观察到独特的杂芳基物质。
<i>B</i>-Alkyl Suzuki−Miyaura Cross-Coupling Reactions with Air-Stable Potassium Alkyltrifluoroborates
作者:Gary A. Molander、Chang-Soo Yun、María Ribagorda、Betina Biolatto
DOI:10.1021/jo0343331
日期:2003.7.1
palladium-catalyzed cross-coupling reaction of substitutedpotassium alkyltrifluoroborates with arylhalides and aryl triflates proceeds readily with moderate to good yields. The potassium alkyltrifluoroborates 1, 2, and 3a-e were easily synthesized and obtained as air-stable crystalline solids that can be stored for long periods of time. All of the cross-couplings proceed under the same reaction conditions using PdCl(2)(dppf)
One-Pot Synthesis of Trisubstituted Conjugated Dienes via Sequential Suzuki−Miyaura Cross-Coupling with Alkenyl- and Alkyltrifluoroborates
作者:Gary A. Molander、Yasuo Yokoyama
DOI:10.1021/jo052636k
日期:2006.3.1
Pd(PPh3)4 is described. This synthetic method proceeds smoothly in one pot under mild reaction conditions to provide the corresponding trisubstituted, conjugated dienes in excellent yield. Moreover, the method is operationally very simple because the organotrifluoroborates are stable in air, and the byproducts are innocuous inorganic salts.
Palladium-catalyzed cross-coupling reaction of alkenyl bromides with potassium alkyltrifluoroborates
作者:Gary A. Molander、Jungyeob Ham、Dave G. Seapy
DOI:10.1016/j.tet.2006.10.088
日期:2007.1
The Suzuki-Miyaura-type cross-coupling reaction of potassium alkyltrifluoroborates with various alkenyl bromides in the presence of 10 mol % of PdCl(2)(dppf).CH(2)Cl(2) and 3.0 equiv of Cs(2)CO(3) in aqueous toluene at 80 degrees C provided the desired compounds in 49-95% yields. A variety of functional groups in the potassium alkyltrifluoroborates were tolerated under the basic conditions.
gold-catalyzed C(sp3)–C(sp2) Suzuki–Miyaura coupling reaction facilitated by ligand-enabled Au(I)/Au(III) redox catalysis was developed. The cross-coupling of alkylorganometallics was first realized in the redox catalytic cycle in gold chemistry, without the use of external oxidants. This gold-catalyzed C(sp3)–C(sp2) coupling reaction allows a variety of alkyl chain and useful methyl trifluoroborates to react