Selective arylation/annulation cascade reactions of 2-alkynylanilines with diaryliodonium salts

An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.

Rhodium(Ⅲ)-catalyzed selective access to isoindolinones via formal [4+1] annulation of arylamides and propargyl alcohols

A mild and efficient oxidative synthesis of isoindolinones has been realized by Rh(III)‐catalyzed C?H activation of benzamides and[4+1]coupling with propargyl alcohols.This coupling system proceeds with broad substrate scope and mild conditions and provides a new approach to access the useful skeleton ofγ‐lactams with a stereogenic center.

Rh(Ⅲ)-Catalyzed sequential ring-retentive/-opening [4+2]annulations of 2H-imidazoles towards full-color emissive imidazo[5,1-a]isoquinolinium salts and AIE-active non-symmetric 1,1-biisoquinolines

Rhodium-catalyzed C4aryl-H activation and ring-retentive annulation of 2H-imidazoles with internal alkynes to build imidazo[5,1-a]isoquinolinium salts with high yields and broad scope has been disclosed.These novel salts serve as new full-color emissive fluorophores(433-633 nm),just by simply modifying the substituents on C3 and C4 positions of isoquinoline ring.Furthermore,these salts can undergo ring-opening C5_(aryl)-H activation/annulation with a different alkyne to form non-symmetric and AIE-active1,1-biisoquinolines,where NH_(4)OAc plays an indispensable role that accounts for Hofmann elimination and imine formation,leading to an unprecedented imine dance:cyclic imine→N-alkenyl imine→NH imine.The15N labelling experiments indicate that the 2ndannulation includes two pathways:N-exchange(major)and N-retention(minor).

双苄叉丙酮与丙二腈[5+1]合成环己酮类化合物的研究

环己酮是重要的化工原料,是生产尼龙6和尼龙66重要中间体,环己酮结构还存在于自然界中,是一类具有多种生物活性的药物骨架。本论文以双苄叉丙酮与丙二腈为原料,以DMF(N,N-二甲基甲酰胺)为溶剂,K_(2)CO_(3)为碱,且在无催化剂的条件下发生[5+1]环化反应,合成了一系列多取代环己酮类化合物,其结构经1 H NMR,^(13)C NMR、HR-MS(ESI)和IR表征,并对该合成反应机理进行了探讨。该合成方法具有宽泛的底物普适性,条件温和,较高的原子经济性和收率高等优势。

Visible Light-Induced[3+2]Annulation Reaction of Alkenes with Vinyl Azides:Direct Synthesis of Functionalized Pyrroles

A photocatalytic[3+2]annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye photocatalysts.Broad substrate scope and high functional group tolerance were demonstrated by more than 50 examples.The reaction provides a novel and efficient method for the synthesis of polyfunctionalized pyrroles under very mild metal-free conditions without other additives.

Metal-Free Photocatalytic[4+2]Annulation of Acrylamides with 2-Benzyl-2-bromocarbonyls to Assemble Tetralin-1-carboxamides

Tetralin-1-carboxamides are frequently incorporated in myriad medicinally important molecules.However,their existing synthetic routes not only suffer from some drawbacks such as tedious procedures,harsh reaction conditions,narrow substrate scope,low yields,and environmental problems,but are also based upon the elaboration of uneasily available non-linear tetralin derivatives.Herein,we describe a metal-and additive-free visible light-induced[4+2]annulation of two simple linear starting materials,namely acrylamides and 2-benzyl-2-bromocarbonyls,through a cascade C(sp^(3))-Br/C(sp^(2))-H bond cleavage,double C-C bond formation,and aromatization sequence.The developed protocol provides a convenient,efficient,and green approach to a variety of tetralin-1-carboxamide derivatives with good functional group compatibility.Importantly,the resulting products could also undergo the Licl-mediated mono-decarboxylative cyclization process to further furnish the architecturally novel bridged polycyclic imides with excellentcis-diastereoselectivities.

Electrochemical Cascade Annulation for the Synthesis of 3-Sulfanylquinoline Derivatives under Mild Conditions

An efficient electrochemical approach has been developed for the construction of 3-sulfanylquinoline derivatives by treating phenylethynylbenzoxazinanones with disulfides in an undivided cell.The protocol provided a convenient route to functionalized quinolines with good functional group tolerance.Moreover,it does not require any metal catalysts or additives,furnishing a series of biologicalquinolines inmoderatetogoodyields.

An Assembly of Pyrano[3,2-b]indol-2-ones via NHC-Catalyzed[3+3]Annulation of Indolin-3-ones with Ynals

We report herein an unprecedented N-heterocyclic carbene-catalyzed formal[3+3]annulation of ynals with N-Ts indolin-3-ones under the oxidation condition affording the functionalized pyrano[3,2-b]indol-2-ones.The alkynyl acylazoliums via the combination of a carbene with ynals in the presence of oxidate proved to be the important intermediates for the success of this transformation.This method features a broad substrate scope and mild conditions,including axially chiral skeletons with suitable substitutions.

Chemoselective synthesis of α-carboline derivatives via hypervalent iodine-catalyzed [3+3] annulation under metal-free conditions

A strategy for the synthesis ofα-carboline derivatives from indole-3-carboxaldehydes and 3-aminocyclohex-2-enones under metal-free conditions has been developed.The combination use of phenyliodine(Ⅲ)diacetate(PIDA)and benzoic acid could significantly facilitate the corresponding[3+3]annulation process.This newly developed strategy featured unextraordinary chemoselectivity,good functional group tolerance and the preservation of the carbonyl group of the ketone substrates,which offers the possibility for further transformation of the products.

Phosphine-Catalyzed [4+3] Annulation Reaction of Indole Derivatives with MBH Carbonates:A Facile Access to Indole-1,2-fused 1,4-Diazepinones and Azepines

A phosphine-catalyzed [4+3] annulation between dinucleophilic indole derivatives and Morita−Baylis−Hillman (MBH) carbonates was discovered by using the N1 and N4′/C4′ nucleophilicities of the indole precursors,in which indoles act as four atom synthons. This protocol provides an efficient and facile access to indole-1,2-fused 1,4-diazepinones and azepines in good to high yields in one step,which illustrates potential synthetic utilities in drug discovery.

铑和铱催化C—H键活化及其与偕二氟亚甲基炔烃的环化反应研究进展

近年来含氟炔烃作为创新偶联剂引起了合成界越来越多的兴趣,其中偕二氟亚甲基炔烃参与的C—H键官能化反应正在迅速发展。总结了过渡金属铑和铱催化偕二氟亚甲基炔烃参与的C—H键活化/环化反应。

共轭炔酮合成七元环产物的串联环合反应

串联环合反应能快速、高效构建复杂结构化合物,从而大幅提高原子经济性,减少多化学过程产生的副产物。七元环结构多存在于药物分子或天然产物中,在合成上仍具有挑战性。共轭炔酮因其特殊的结构而具有较高的反应活性和多样的反应方式。综述了2019—2023年以来,在多种碱、膦试剂、氯化金催化剂、氧化剂的催化作用下,共轭炔酮经串联环合反应高效率构建苯并氧杂七元环、苯并氮杂七元环、七元环醇和环庚酮骨架的方法,为探索炔酮的反应性和构筑七元环结构提供重要参考。

Synthesis of 9,10-Phenanthrenes via Rh(III)-Catalyzed[4+2]Annulation of 2-Biphenylboronic Acids with Diazo Compounds

A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kinds of 9,10-phenanthrenes.Notably,a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine,which was further verified to be active for the catalytic system.The reactions proceeded under redox-neutral and air-tolerant conditions to produce a series of all-carbon six-membered rings with high efficiency.

三组分“一锅法”合成苯并二氢吡喃衍生物

报道了一种无金属参与下的三组分“一锅法”合成苯并二氢吡喃衍生物的方法.以水杨醛、芳基亚磺酸钠、1-芳磺酰基烯丙基溴为原料,在1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)作用下,经取代、Knoevenagel缩合、oxa-Michael加成三步反应,以51%~86%的产率合成了15个结构新型的3-芳磺酰基-2-芳磺酰甲基-2H-苯并吡喃衍生物,产物结构经^(1)H NMR、^(13)C NMR和HRMS表征.研究表明,该方法学具有较好的底物普适性,可以进行克级放大,为苯并二氢吡喃衍生物的合成提供了一种高效、反应条件温和、环境友好的合成方法.

TBAI/H_(2)O-cooperative electrocatalytic decarboxylation coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines

The first example of TBAI/H_(2)O cooperative electrocatalytic coupling-annulation of quinoxalin-2(1H)-ones with N-arylglycines was developed. A broad range of tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones were obtained in good to excellent yields with exclusive chemoselectivities and excellent regioselectivities. The H-hydrogen bond served as a key factor for the electrocatalytic production of aminomethyl radical at lower oxidative potential.

High tension cyclic hydrocarbons synthesized from biomass-derived platform molecules for aviation fuels in two steps

Synthesizing ring structure aviation fuels from biomass-derived platform molecules is challenging,especially for bridged ring structure aviation fuels which are typically achieved from fossil-derived chemicals.Herein,we report the synthesis of a series of ring structure biofuels in two steps by a combination of a solvent-free Michael-cyclization reaction and a hydrodeoxygenation(HDO)reaction from lignocellulosederived 5,5-dimethyl-1,3-cyclohexanedione.These biofuels are obtained with high overall yields up to 90%,which exhibit high densities of 0.81 g cm^(-3)-0.88 g cm^(-3)and high volumetric neat heat of combustion(VNHOC)values of 36.0 MJ L^(-1)-38.6 MJ L^(-1).More importantly,bridged-ring structure hydrocarbons can also be achieved in two steps by a combination of a Robinson annulation reaction and an HDO reaction to afford the final products at high overall yields up to 90%.The bridged-ring structure products have comparable high densities and high VNHOC values to the best artificial fuel JP-10(0.94 g cm^(-3)and 39.6 MJ L^(-1)).The results demonstrate a promising way for the synthesis of high-density aviation fuels with different fuel properties at high yields.

银催化炔酮的自由基烷基化/5-endo环化反应研究

为了通过炔酮高效合成环戊酮衍生物,开发了一个银催化炔酮的自由基烷基化/5-endo环化反应.反应以芳基炔酮和烷基羧酸为原料,通过烷基羧酸氧化脱羧产生烷基自由基、自由基对炔酮加成、1,5-氢迁移、5-endo环化、分子间氢迁移或还原质子化等步骤,高非对映选择性地构建了α-烷基环戊酮衍生物.结果表明:该环化反应的效率较高,产率最高可达83%;反应的官能团兼容性良好,适用于多种炔酮与烷基羧酸.此环化反应的发展为复杂多取代环戊酮衍生物的高效构筑提供了新思路.

隐瞒重疾可撤销条款的认定困境及解决--基于裁判实证类型化梳理

为保障婚姻自由和诚信,民法典完成了从“重疾禁婚”到“隐瞒重疾可撤婚”的立法态度转变。因法无明文规定,重疾的认定在司法实践中普遍以疾病类型为认定标准的一刀切式的裁判逻辑,违背了立法的预期与初衷。重疾的司法认定不应回避其所涉及的价值判断衡量,应从婚姻“共同生活”的目的入手,结合婚后形成的夫妻权利义务的实现,综合分析疾病对婚姻当事人婚后物质共同生活与精神共同生活的影响,同时辅以其他法律法规的类型参考,以期对重疾司法认定提供新的方法路径,完满实现立法初衷。

Facile synthesis and functionalization of fluoranthenes via intramolecular[4+2]annulations between thiophenes and alkynes

Fluoranthenes have attracted tremendous attention due to their unique optoelectronic properties and extensive applications.Although several synthetic methodologies have been developed for the preparation of fluoranthene derivatives,it is still unfavorable to functionalize the fluoranthene framework at different positions due to the relatively low selectivity and reactivity.Herein,a catalyst-free intramolecular[4+2]annulation between thiophenes and alkynes is developed towards the synthesis of fluoranthenes.Altogether 20 examples have been demonstrated using this method.Various functional groups can be precisely introduced into the fluoranthene skeleton at different positions by simply tuning the substituents on the thiophenes and alkynes.The conjugation of the fluoranthene can be facilely extended through different directions.Furthermore,the feasibility of this[4+2]annulation reaction is also investigated by density functional theory calculations.Therefore,this protocol provides not only a synthetic methodology towards fluoranthenes with substituents functionalized at different positions,but also an effective pathway to construct large polycyclic aromatic hydrocarbons containing fluoranthene moieties.