Radical Chain Reduction of Alkylboron Compounds with Catechols
作者:Giorgio Villa、Guillaume Povie、Philippe Renaud
DOI:10.1021/ja110224d
日期:2011.4.20
carboxylic acid at high temperature (>150 °C). We report here a mild radical procedure for the transformation of organoboranes to alkanes. 4-tert-Butylcatechol, a well-established radical inhibitor and antioxidant, is acting as a source of hydrogen atoms. An efficient chain reaction is observed due to the exceptional reactivity of phenoxyl radicals toward alkylboranes. The reaction has been applied to a wide
烷基硼烷向相应烷烃的转化通常通过烷基硼烷的质子分解进行。这个简单的反应需要使用严格的反应条件,即在高温(> 150 °C)下用羧酸处理。我们在这里报告了一种将有机硼烷转化为烷烃的温和激进程序。4-叔丁基儿茶酚是一种成熟的自由基抑制剂和抗氧化剂,是氢原子的来源。由于苯氧基自由基对烷基硼烷的特殊反应性,观察到有效的链式反应。该反应已应用于广泛的有机硼衍生物,例如 B-烷基儿茶酚硼烷、三烷基硼烷、频哪醇硼酸酯和烷基硼酸。此外,迄今为止,通过实验确定了仲烷基自由基和邻苯二酚衍生物之间的氢转移的难以捉摸的速率常数。有趣的是,它们在 80 °C 时比氢化锡慢不到 1 个数量级,这使得儿茶酚对涉及 CC 键形成的广泛转化特别有吸引力。
m-C2B10H11HgCl/AgOTf-Catalyzed Reaction for Reductive Deoxygenation
A m -C 2 B 10 H 11 HgCl/AgOTf-catalyzed reaction of allyl silyl ethers with N -Boc- N ′-tosylhydrazine has been developed. Under mild conditions, the resulting allyl hydrazine products were transformed into naked alkenes in good yield. Furthermore, the used m -C 2 B 10 H 11 HgCl could be recovered quantitatively.
已开发出 m -C 2 B 10 H 11 HgCl/AgOTf 催化的烯丙基甲硅烷基醚与 N -Boc-N '-甲苯磺酰肼的反应。在温和的条件下,所得的烯丙基肼产物以良好的收率转化为裸烯烃。此外,使用过的m -C 2 B 10 H 11 HgCl 可以定量回收。
Copper-Mediated and -Catalyzedo-DPPB-Directed Allylic Substitution
Complete control of chemo-, regio- and stereoselectivity in the course of copper-catalyzed and -mediated allylic substitution could be obtained with the ortho-diphenylphosphanyl (o-DPPB) function as a reagent-directing leaving group. Complete chirality transfer by way of a syn-addition process has been achieved for cyclic and acyclic systems. Readily available Grignardreagents may be employed as nucleophiles
Regio and stereospecific synthesis of and 3-methyl-6-methylethyl cyclohexenes and 3-methyl-4-methylethylcyclohexenes. Reactions of allylic acetates and carbamates with Li2Cu3Me5 and LiCuMe2
作者:C. Gallina
DOI:10.1016/s0040-4039(00)87541-3
日期:1982.1
The isomeric alkenes 1–4 have been obtained by syn, γ substitution of the appropriate allylic carbamates with Li2Cu3Me5. The behaviour of carbamates is deeply affected by the nature of the copper reagent.
异构烯烃1-4是通过用Li 2 Cu 3 Me 5对适当的烯丙基氨基甲酸酯进行γ合成,γ取代而获得的。氨基甲酸酯的行为深受铜试剂性质的影响。
Radical Deoxychlorination of Cesium Oxalates for the Synthesis of Alkyl Chlorides
作者:Justin Y. Su、Denise C. Grünenfelder、Kohei Takeuchi、Sarah E. Reisman
DOI:10.1021/acs.orglett.8b02045
日期:2018.8.17
A radical deoxychlorination of cesium oxalates has been developed for the preparation of hindered secondary and tertiaryalkylchlorides. The reaction tolerates a number of functional groups, including ketones, alcohols, and amides, and provides complementary reactivity to standard deoxychlorination reactions proceeding by heterolytic mechanisms. Preliminary studies demonstrate that the developed conditions