无金属和氧化剂温和条件下碱促进的烯胺酮碳-碳双键断裂合成NH_2-结构脒类化合物（英文）

报道了室温条件下烯胺酮和磺酰叠氮通过碳-碳双键断裂合成N-磺酰基醚类化合物的方法.反应在1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)存在下进行,无需使用任何金属和氧化剂,具有良好的底物适用性.烯胺酮上的~(15)N同位素标记实验证实,磺酰叠氮仅作为产物中的磺酰胺片段供体,同时,该实验也有力地支持反应机理涉及关键的1,2,3-三唑啉中间体的原位形成以及环分解.     

烯胺调控下和对甲苯磺酰叠氮在纯水介质中的无金属环化反应合成1,2,3-三氮唑(英文)

通过使用简单的Et_3N催化容易获得的β-取代NH-烯胺酯和对甲苯磺酰叠氮的反应,高效实现了全取代的1,2,3-三氮唑的合成.在该方法中,水用作反应的唯一介质,以高底物适用性和中等至优秀的产率合成了1,2,3-三氮唑产物.对照实验表明,使用稳定的NH-烯胺作为底物,可能是通过NH基团与水之间的氢键作用实现水介导反应的关键因素.研究还发现,在相同条件下经由相应的N-烷基烯胺酯和对甲苯磺酰叠氮的反应,选择性地生成N-烷基磺酰胺.     

铜催化的烯丙醇自由基胺化/1,2-碳迁移串联反应:一步构建含α-季碳中心的β-胺基酮（英文）

烯丙醇类化合物是非常重要的有机合成砌块.近年来,自由基或阳离子对烯丙醇类化合物的加成引发的1,2-碳迁移反应迅速发展,被认为是合成含α-季碳中心的β-羰基化合物最有效的策略之一.目前,烯丙醇的官能团化/1,2-碳迁移反应取得了很好的成果,各种官能团化反应,比如卤化、三氟甲基化、硫化、膦化和芳基化等,已经顺利实现.但是,烯丙醇类化合物的胺化/1,2-碳迁移串联反应研究较少.这可能是由于竞争的亲核胺化反应存在导致的.因此,发展烯丙醇类化合物的胺化串联反应值得期待.我们及其他课题组以N-氟代双苯磺酰亚胺(NFSI)作为有效的自由基氮源,实现了烯烃或炔烃的自由基胺化官能团化反应.研究表明,在铜催化温和条件下即可生成金属稳定的氮中心自由基物种.据此,我们认为,在温和条件下有效产生氮中心自由基是实现烯丙醇自由基胺化/1,2-碳迁移串联反应的关键.在前期工作基础上,本文利用NFSI及其衍生物作为有效的自由基胺化试剂,实现了铜催化烯丙醇类化合物的自由基胺化/1,2-碳迁移串联反应,直接构建重要的含α-季碳中心的β-胺基酮骨架.本文合成了24个不同官能团取代的β-胺基酮衍生物.反应中芳环上取代基的电子效应和空间效应表现并不明显.当芳基对位连有卤素、烷氧基、芳基、烷基时,或者邻位和间位甲基取代的1-(1-芳基烯基)环丁醇均可以与NFSI顺利反应,以中等至较高的产率得到相应的含α-季碳中心的β-胺基酮.氧杂环丁醇、取代的环丁醇类化合物,5元、6元及非环状的苯基烯丙醇类化合物均适用于该反应,生成相应的目标化合物.同时,我们也扩展了胺化试剂的范围,除NFSI衍生物外,单取代的NFHSO2Ph类型氮源也可以有效发生自由基胺化/1,2-碳迁移串联反应,生成目标产物.另外,扩大反应物的量至5 mmol,反应不受影响,仍能以90%的产率生成β-胺基酮衍生物.最后,通过控制实验捕捉到反应中生成的苄基自由基中间体,表明该反应经历氮中心自由基对烯丙醇烯烃双键的区域选择性加成引发的1,2-碳迁移串联反应.总之,本文以N-F试剂作为自由基胺化试剂,利用铜催化体系发展了烯丙醇类化合物的自由基胺化/1,2-碳迁移串联反应,一步合成了重要的β-胺基酮类化合物.该反应条件温和,底物适用范围宽泛,官能团兼容性较好,合成了一系列链状、环状及螺环的含有α-季碳中心的β-胺基酮衍生物.据我们所知,这是首例将NHFSO_2Ph类型N-F试剂作为自由基氮源的反应.     

氟烷基磺酰叠氮的化学反应研究

氟烷基磺酰叠氮可以与一系列亲核试剂,烯胺、烯基硅醚等富电子烯烃进行独特的反应,并且能够在温和条件下将含氟基团引入到有机分子中。     

碳-碳重键的新合成方法学研究

本研究工作包括下列8方面:(1)一种不同于Wittig反应的新的烯化方法,含氟β-酮基磷盐在有机合成中的应用。(2)"一锅"法的碳-碳双键形成反应。(3)一种新的叶立德阴离子的形成方法。(4)消去三苯基胂形成碳-碳双键的合成方法学。(5)立体选择性地控制合成(Z)或(E)-碳-碳双键化合物的新方法。(6)亲核试剂对全氟酰基膦酸酯进攻为基础的新合成方法学。(7)还原烯化反应的合成方法学。(8)含氟碳-碳叁键的合成方法学。     

桃小食心虫性信息素——(Z)-7-二十碳烯-11-酮的简便合成

桃小食心虫是危害最大的果树害虫之一,其性信息素主要成分为(Z)-7-二十碳烯-11-酮.从2,3-二氢呋喃出发,经酸水解得到4-羟基丁醛,与正庚基三苯基溴化磷制备的Wittig试剂反应得到(Z)-4-十一碳烯-1-醇,经氧化得到(Z)-4-十一碳烯醛,再经格氏加成得到(Z)-7-二十碳烯-11-醇,氧化后得到目标产物.     

顺式环十二碳烯的构象

用分子力学法(MMX程序)计算了15-苯基双环[10,3,0]十五碳-1(12)-烯-13-酮,其分子中环十二碳烯部分的构象为能量最低的[l_(ene)2333],与X衍射结果吻合.同时,还计算了15个顺式环十二碳烯的构象,求出了它们的能量及结构参数,讨论了影响构象稳定性的因素.     

新型3-烯色满酮拼接季碳氧化吲哚类化合物的合成

以色酮取代氧化吲哚（1）为原料,在有机碱DABCO的催化作用下,进攻3-烯色满酮2的烯键,发生Michael加成反应,然后脱除OBoc基团生成烯键,合成了9个未见文献报道的3-烯色满酮拼接季碳氧化吲哚类化合物（3a～3i）,产率60%～87%,dr值为2:1～5:1,其结构经1H NMR,13C NMR和HR-MS（E...     

钯催化下全氟碳负离子的产生及其反应

2-三氟甲基-3-氧杂-八氟己酸烯丙酯或2,5-二(三氟甲基)-3,6-二氧杂-十二氟壬酸烯丙酯可在钯的作用下产生相应的全氟碳负离子. 这些碳负离子能够质子化或者对取代苯甲酰氯发生亲核进攻, 后者为芳基氟烷基酮的合成提供了一条简捷途径. 另一方面,上述含氟酸的甲酯和取代苯甲酰氯在钯的作用下同样能发生反应而生成相应的芳基氟烷基酮.     

双环[10,3,0]十五碳-1(12)-烯-13-酮系列化合物的合成

以多聚磷酸为催化剂,通过环十二碳烯和α,β-不饱和酸的反应,合成了十个双环[10.3.0]十五碳-1(12)-烯-13-酮系列化合物,研究了合成反应的条件及产物的分离提纯方法,并测定了它们的紫外光谱、红外光谱以及~1H核磁共振谱。     

MnO2‐Promoted Oxidative Radical Sulfonylation of Haloalkynes with Sulfonyl Hydrazides: C(sp)–S Bond Formation towards Alkynyl Sulfones

A catalyst‐free oxidative radical sulfonylation of haloalkynes with sulfonyl hydrazides is reported. It represents an example of C(sp)−S bond formation using sulfonyl hydrazides as sulfonyl radical sources. Various alkynyl sulfones were synthesized in moderate to good yields. Having MnO₂ as the oxidant is very critical for this transformation. Remarkably, the self‐coupling reaction of haloalkynes through C(sp)−C(sp) bond formation is significantly inhibited under the standard reaction conditions.     

Photocatalytic C−C Cleavage of Methylenecyclobutanes for γ,δ-Unsaturated Aldehydes by Strain Release

Radical additions onto olefins have surfaced as an increasingly powerful strategy for the synthesis of difunctionalized scaffolds. However, despite of major advances, known approaches continue to be largely limited to two manifolds, namely 1,2-difunctionalization of alkenes and remote difunctionalization via hydrogen atom transfer (HAT). Herein, we describe a mechanistically distinct approach by photoinduced carbon-carbon (C−C) activation/ring-opening to access γ,δ-unsaturated aldehydes from methylenecyclobutanols and sulfonyl chlorides by strain release. Remarkably, the sulfonyl motif on the products was easily removed by another photocatalytic process, which enabled the concise assembly of the natural product alatanone A. The synthetic utility of our approach was reflected by versatile functional group tolerance, ample substrate scope, and scalability. The photocatalysis represents a conceptually distinct alternative to existing approaches for remote 1,4-diversifications, with a double bond remaining in the thus obtained products.     

Bis‐Sulfonyl O,C,O‐Chelated Metallylenes (Ge,Sn) as Adjustable Ligands for Iron and Tungsten Complexes

The synthesis and characterization of an E₂CE₂ bis‐sulfonyl aryl pincer ligand and its efficiency for the stabilization of compounds containing low‐valent Group 14 elements (Ge and Sn) are reported. Complexation reaction of these metallylenes with iron or tungsten complexes resulted in the modulation of the oxygen atoms of the sulfonyl groups implicated in the stabilization of the Group 14 elements, demonstrating the original adjustable character of the bis‐sulfonyl O₂S‐C‐SO₂ aryl pincer.     

Sulfonyl Nitrene and Amidyl Radical: Structure and Reactivity

Photocatalytic generation of nitrenes and radicals can be used to tune or even control their reactivity. Photocatalytic activation of sulfonyl azides leads to the elimination of N₂ and the resulting reactive species initiate C−H activations and amide formation reactions. Here, we present reactive radicals that are generated from sulfonyl azides: sulfonyl nitrene radical anion, sulfonyl nitrene and sulfonyl amidyl radical, and test their gas phase reactivity in C−H activation reactions. The sulfonyl nitrene radical anion is the least reactive and its reactivity is governed by the proton coupled electron transfer mechanism. In contrast, sulfonyl nitrene and sulfonyl amidyl radicals react via hydrogen atom transfer pathways. These reactivities and detailed characterization of the radicals with vibrational spectroscopy and with DFT calculations provide information necessary for taking control over the reactivity of these intermediates.     

Ruthenium‐Catalyzed C7 Amidation of Indoline CH Bonds with Sulfonyl Azides

A ruthenium‐catalyzed direct C7 amidation of indoline C?H bonds with sulfonyl azides was developed. This procedure allows the synthesis of a variety of 7‐amino‐substituted indolines, which are useful in pharmaceutical. The good functional tolerances, as well as the mild conditions, are prominent feature of this method.     

A Bis‐Sulfonyl O,C,O Aryl Pincer Ligand and its Tin(II) Complex: Synthesis,Structural Studies,and DFT Calculations

The efficiency of the deprotonated aryl bis‐sulfone [2,6‐{(p‐tolyl)SO₂}₂C₆H₃]^? as an O,C,O‐coordinating pincer‐type ligand was described. The bis‐sulfone precursor was synthesized using a straightforward palladium‐catalyzed cross‐coupling reaction. As a result of directed ortho metalation (DoM) through sulfonyl groups, a selective lithiation of the aryl group was achieved and the corresponding carbanion was isolated and its structure determined by single‐crystal X‐ray diffraction analysis. A heteroleptic tin(II) complex has been prepared by a nucleophilic substitution reaction. Crystallographic analysis and DFT calculations indicate that the bis‐sulfonyl moiety acts as a new O,C,O‐coordinating pincer‐type ligand with intramolecular S?O coordination to a tin(II) center. The cis form with the two nonbonded oxygen atoms of the sulfonyl groups on the same side is preferentially obtained.     

A Bis‐Sulfonyl O,C,O Aryl Pincer Ligand and its Tin(II) Complex: Synthesis,Structural Studies,and DFT Calculations

The efficiency of the deprotonated aryl bis‐sulfone [2,6‐{(p‐tolyl)SO₂}₂C₆H₃]⁻ as an O,C,O‐coordinating pincer‐type ligand was described. The bis‐sulfone precursor was synthesized using a straightforward palladium‐catalyzed cross‐coupling reaction. As a result of directed ortho metalation (DoM) through sulfonyl groups, a selective lithiation of the aryl group was achieved and the corresponding carbanion was isolated and its structure determined by single‐crystal X‐ray diffraction analysis. A heteroleptic tin(II) complex has been prepared by a nucleophilic substitution reaction. Crystallographic analysis and DFT calculations indicate that the bis‐sulfonyl moiety acts as a new O,C,O‐coordinating pincer‐type ligand with intramolecular SO coordination to a tin(II) center. The cis form with the two nonbonded oxygen atoms of the sulfonyl groups on the same side is preferentially obtained.     

Radical Mediated Diastereoselective Synthesis of Benzothiazole Sulfonyl Ethyl C‐Glycosides

Diastereoselective synthesis of a variety of benzothiazole sulfonyl ethyl C‐glycosides has been developed by a radical mediated approach on the reaction of glycosyl bromides and benzothiazolyl vinyl sulfone in the presence of n‐Bu₃SnH and AIBN in good yields.     

N‐Methyl‐N‐(1‐phenyl­sulfonyl­indol‐2‐ylmethyl)­aniline

In the title compound, 2‐[(methylphenylamino)methyl]‐1‐(phenylsulfonyl)indole, C₂₂H₂₀N₂O₂S, the indole system is not strictly planar and the dihedral angle between the fused rings is 2.7 (1)°. The angles around the S atom of the sulfonyl substituent deviate significantly from the ideal value for tetrahedral geometry. The pyramidalization at the indole N atom is very small. Of the two C—H?O interactions, one influences the orientation of indole with respect to the sulfonyl group and the other determines the orientation of the phenyl bound to sulfonyl. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 89.6 (1)° with the best plane of the indole. The molecular packing is stabilized by C—H?π and C—H?O hydrogen bonds.     

碳碳双键催化加氢的研究进展

综述了近年来碳碳双键催化加氢的研究进展;分别针对以氢气为氢源的催化加氢反应和以非氢气为氢源的催化转移加氢反应进行了分析概括;指出其中催化转移加氢(包括光照下转移加氢)具有反应条件温和且操作安全简便的优势,应用前景广阔.