Synthesis and spectroscopic properties of 1,4-diarylbutenynes
作者:Alois H. A. Tinnemans、Wim H. Laarhoven
DOI:10.1039/p29760001104
日期:——
Several new diarylbutenynes have been synthesized and analyses of the n.m.r. and u.v. spectra are described. For planar trans-isomers a conformational preference was found for 1-(α-naphthyl)- but not for 1-(β-naphthyl)-4-arylbutenynes. This difference is also found between compounds with C-1 attached to the α- or β-position of a larger aryl group.
Mono- and Bimetallic Aluminum Alkyl, Alkoxide, Halide and Hydride Complexes of a Bulky Conjugated Bis-Guanidinate(CBG) Ligand and Aluminum Alkyls as Precatalysts for Carbonyl Hydroboration
easily deprotonated (at least two protons) upon treatment with metal reagents. Both mono- and dinuclear aluminum alkyls and mononuclear aluminum alkoxide, halide, and hydridecomplexes have been structurally characterized. Further, we have demonstrated the potential of mononuclear, six-membered CBG aluminum dialkyls in catalytic hydroboration of a broad range of aldehydes and ketones with pinacolborane (HBpin)
四芳基取代的对称共轭双胍(CBG)配体,例如L 1–3(3H)[L(3H)= (ArHN)(ArHN)C═N–C═NAr(NHAr)};Ar = 2,6-Me 2 -C 6 H 3(L 1(3H)),2,6-Et 2 -C 6 H 3(L 2(3H))和2,6- i Pr 2 -C 6 ħ 3(L 3(3H))]已被用于合成一系列的四和六元杂环铝(1 - 8),用于在第一时间。通常,带有N,N的铝配合物che-螯合的胍盐和β-二酮/二吡咯亚甲基配体系统分别形成四元和六元杂环。然而,共轭双胍配体具有在同一分子内形成具有多金属中心的四元和六元杂环的能力。这是由于存在三个酸性质子,它们在用金属试剂处理后很容易被去质子化(至少两个质子)。单核和双核烷基铝和单核铝醇盐,卤化物和氢化物络合物均已进行结构表征。此外,我们已经证明了单核六元CBG铝二烷基酯在与频哪醇硼烷(HBpin)催化的广泛醛和酮的硼氢化反应中的潜力。
Biomimetic Synthesis of Lankacidin Antibiotics
作者:Kuan Zheng、Defeng Shen、Ran Hong
DOI:10.1021/jacs.7b08500
日期:2017.9.20
We devised short syntheses of lankacidinol and lankacyclinol that feature biomimetic Mannich macrocyclization. The modular construction of the carbon framework of these compounds is amenable to rapid structural diversification for the development of antibiotic and antitumor agents.
Collective synthesis of natural products by means of organocascade catalysis
作者:Spencer B. Jones、Bryon Simmons、Anthony Mastracchio、David W. C. MacMillan
DOI:10.1038/nature10232
日期:2011.7
Organic chemists are now able to synthesize small quantities of almost any known natural product, given sufficient time, resources and effort. However, translation of the academic successes in total synthesis to the large-scale construction of complex natural products and the development of large collections of biologically relevant molecules present significant challenges to synthetic chemists. Here we show that the application of two nature-inspired techniques, namely organocascade catalysis and collective natural product synthesis, can facilitate the preparation of useful quantities of a range of structurally diverse natural products from a common molecular scaffold. The power of this concept has been demonstrated through the expedient, asymmetric total syntheses of six well-known alkaloid natural products: strychnine, aspidospermidine, vincadifformine, akuammicine, kopsanone and kopsinine. By combining two biosynthetic principles that have evolved in the natural world, David MacMillan and colleagues at the Merck Center for Catalysis at Princeton University, New Jersey, have developed a powerful strategy for the production of a broad spectrum of natural products. The first technique is organocascade catalysis, in which a continuous catalytic cascade replaces the traditional stop-go method of synthesis. The second is collective synthesis, in which a general synthetic route is used to reach a common molecular scaffold that, with appropriate fine-tuning, serves as a conduit to other members of the same chemical family. The method is demonstrated with the asymmetric total syntheses of six high-profile alkaloids: strychnine, aspidospermidine, vincadifformine, akuammicine, kopsanone and kopsinine.
Iron(III) Chloride-Catalyzed Tandem Aza-Prins/Friedel-Crafts Cyclization of 2-Arylethyl-2,3-butadienyl Tosylamides and Aldehydes-An Efficient Synthesis of Benzo[<i>f</i>]isoquinolines
作者:Weilong Lin、Jiajia Cheng、Shengming Ma
DOI:10.1002/adsc.201600107
日期:2016.6.16
An efficient approach for the synthesis of 1,2,3,4,5,6‐hexahydrobenzo[f]isoquinolines via a tandem aza‐Prins/Friedel–Crafts cyclization from 2‐arylethyl‐2,3‐butadienyl tosylamides and aldehydes has been developed. This iron(III) chloride‐catalyzed cascade cyclization at the room temperature with different types of aldehydes, such as aromatic and heteroaromatic aldehydes, alkyl aldehydes, and α,β‐unsaturated
一种有效的方法是通过 串联的aza-Prins / Friedel-Crafts环合反应由2-芳基乙基-2-3,3-丁二烯基甲苯磺酰胺和醛合成1,2,3,4,5,6-六氢苯并[ f ]异喹啉。发达。这种氯化铁(III)在室温下与不同类型的醛(例如芳族和杂芳族醛,烷基醛和α,β-不饱和醛)催化的级联环化反应,可提供中等至优异收率的产品(最高97 %)。在该反应中,使用三甲基氯硅烷活化醛。廉价的催化剂,温和的反应条件和广泛的底物范围使该方法非常有用。