Studies on New Additions to 5-Methoxy-2 (5H)-Furanone: 1, 4-Addition of Grignard Reagents, and 1,3-Dipolar Cycloaddition of Silyl Nitronates

1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.

Synthesis of Novel Discotic C_(60)-triphenylene Derivative by 1,3-Dipolar Cycloaddition

1 Introduction Fullerene has received considerable attention and a great researching interest due to its unique structure and interesting properties[1―3]. Many functional groups have been introduced, often region- or stereo-selectively, for tuning the physical properties of C60and for constructing supramoleculararchitectures^[4-6].

ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION REACTION BY A CHIRAL SOURCE,5-(1-MENTHYLOXY)-2(5-H)-FURANONE

5-(1-Menthyloxy)-2(5-H)-furanone is used as s chiral dipolarophile for thermal asymmetric 1,3-dipolar cycloaddition reaction with C-phenyl-N-phenyl nitrone to give the diastereomerically pure cycloaddition product.

A FACILE SYNTHESIS OF 2-TRIFLUOROMETHYLPYRROLE VIA 1,3-DIPOLAR CYCLOADDITION REACTION OF 2-TRIFLUOROMETHYLOXAZOLONE AND THE ACTIVATED CARBON-CARBON MULTIPLE BOND

The 1.3-dipolar cycloaddition reaction of 2-trifluoromethyl- oxazolone and the activated carbon-carbon multiple bond was studied and gave a convenient way to synthesize 2-trifluoromethylpyrrole derivatives.

1,3-Dipolar Cycloaddition Reaction between Vinyl Acetate and N-Alkyl Hydroxypyridinium Halide

1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition, This reaction has been successfully used on the synthesis of an analogue of Bao-Gong-Teng A.

Asymmetric 1,3-Dipolar Cycloaddition of the Chiral Nitronic Esters with Acrylate

Asymmetric 1,3-dipolar cycloaddihon of the chiral nitronic esters with acrylate giving the enantiomerically pure novel chiral bisheterocyclic compounds is describcd

Theoretical Study of 1,3-Dipolar Cycloaddition of Hydrazoic Acid to Substituted Ynamines

有水螅的各种各样的代替的 ynamines 的 1,3-dipolar 出租机动三轮车增加反应动物的酸理论上与高精确性的 CBS-QB3 方法被调查。代替的二 regioisomers， 4 胺，和 5 胺使内收，被获得，与是的前者比较喜欢的收益。这 regioselectivity 被边疆文饰分子的轨道的理论。反应和 synchronicity 在 ynamine 碎片上随代用品的撤退电子的特性的增加被提高。计算也证明溶剂的效果增加激活精力，并且反应在极的溶剂更努力变得平。

Copper-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides withβ-trifluoromethyl-substituted alkenyl heteroarenes

Copper-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides andβ-trifluoromethyl-substituted alkenyl heteroarenes was developed for the first time.A wide range of enantioenriched pyrrolidines containing both heteroarenes and trifluoromethyl group with multiple stereogenic centers could be readily accessible by this method with good to high yields and excellent levels of both stereo-and regioselectivity(up to 99%yield,>20:1 rr,>20:1 dr,and up to 95%ee).Notably,substratecontrolled umpolung-type dipolar cycloaddition was also disclosed in this protocol to achieve regiodivergent synthesis withα-aryl substituted aldimine esters as the dipole precursors.Systematic DFT studies were conducted to explore the origin of the stereo-and regioselectivity of this 1,3-dipolar cycloaddition,and suggest that copper(Ⅱ)salt utilized in this catalytic system could be reduced in-situ to the active copper(Ⅰ)species and might be responsible for the observed high stereo-and regioselectivity.

A Facile Synthesis of Indolizines by 1，3－Dipolar Cycloaddition of Pyridinium and Related Heteroaromatic Ylides with Alkenes in the Presence of TPCD，Py_4Co（HCrO_4）_2

facile one-step method is presented for the synthesis of indolizines in moder-ate to high yields by reaction of pyridinium, quinolinium and isoquinolinium ylideswith acrylonitrile, methyl acrylate and diethyl maleate respectively in the presenceof tetrakis-pyridino-cobalt(Ⅱ)dichromate (TPCD) in DMF.

The Chemistry of Tetrafluoroallene:One-pot Synthesis of Trifluoromethylindolizines from 1,3-Diiodo-1,1,3,3-tetrafluoropropane by 1,3-Dipolar Cycloaddition

Heating a mixture of 1, 3-diiodo-1 ,1,3, 3-tetrafluoropropane (2), K2CO3, pyridinium bromides (3) in CH3CN at 65℃ for 10 h gives the corresponding trifluoromethylindolizines.

催化邻羟基苯基取代对亚甲基醌与酮亚胺环加成反应合成二氢-1,3-苯并噁嗪化合物

发展了邻羟基苯基取代对亚甲基醌与酮亚胺在磷酸催化体系中的[4+2]环加成反应,以高产率和优良的非对映选择性得到了一系列二氢-1,3-苯并噁嗪化合物.当向反应体系加入催化量的B(C_(6)F_(5))_(3)时,产物的产率得到保持且发生非对映选择性翻转.

Synthesis of novel N-pyridylpyrazole derivatives containing 1,2,4-oxadiazole moiety via 1,3-dipolar cycloaddition and their structures and biological activities

A series of novel 1,2,4-oxadiazole-containing N-pyridylpyrazole derivatives 12 a-h were efficiently synthesized with pivaldehyde,pyridylpyrazole carboxylic acid and arylamine as raw materials via 1,3-dipolar cycloaddition.Their structures were identified by melting points,1 H NMR,13 C NMR and elemental analysis or HRMS.The exploration on the single-crystal structures of 12 c and 12 g revealed the stereochemical and substituent oriental characteristics,and the relevance of the structure and the reaction activity of this type of compounds.The preliminary bioassays indicated that several compounds had good insecticidal activities,among which 12 c showed a lethality rate of 80%towards Mythimna separata Walker at 200μg/mL;some of the compounds exhibited favorable fungicidal activities at 50μg/mL against Physalospora piricola,Rhizoctonia cereal,Sclerotinia sclerotiorum,etc.Among which,12 a,12 b,12 c and 12 h could be considered as new fungicidal leading compounds for further structural optimization.These discoveries along with the structure-activity relationship analysis in this paper will provide useful guidance for the innovative studies on new pyridylpyrazole derivatives and their applications in agrochemical area.

Diastereoselective Synthesis of 1,10-Dihydropyrrolo [ 1,2-a] [1,10]phenanthroline Derivatives via 1,3-Dipolar Cycloaddition Reaction

The functionalized 1,10-dihydropyrrolo[1,2-a][1,10]phenanthroline derivatives were synthesized in good yields and with high diastereoselectivity by 1,3-dipolar cycloaddition reactions of N-phenacylphenanthrolinium bromides or N-ethoxycarbonylmethylene phenanthrolinium bromide with various nitrostyrenes in acetonitrile at room temperature in the presence of triethvlamine,

Design, Synthesis and Properties of Novel C60-Crown Dyads by 1,3-Dipolar Cycloaddition

Based on the 1,3-dipolar cycloaddition of azomethine ylide generated in situ from aldehyde and sarcosine attached to C60,two novel benzo-15-crown-5/C60 dyads with a different linking chain in each were designed and synthesized in yields of 30％ and 38％,respectively.It was found that their UV-Vis absorption spectra could be regulated hypsochromically by metal ions complexed.The long and soft linking chain was favorable for cooperate interaction of crown ether unit and C60 unit.

Synthesis of Novel Spiro Thiazolo[3,2-a][1,3,5]triazines via 1,3-Dipolar Cycloaddition of Azomethine Ylide

The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6（7H）-ones afforded novel dispiro[acenaphthylene-1,2’-pyrrolidine]-3＇,7″-[1,3]thiazolo[3,2-a][1,3,5]triazines in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis and X-ray crystallographic analysis. The results of experiment indicated that this 1,3-dipolar cycloaddition proceeded with high stereoselectivity and regioselectivity.

Catalyst-free and atom-economical 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines:Facile synthesis of isoquinoline-fused spirocycles

A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quaternary spiro-carbon centers.All these transformations can be smoothly performed in ethanol at room temperature,providing a catalyst-free and atom-economical access to diversely substituted novel isoquinoline-fused spirocycles in almost quantitative yields with high diastereoselectivities.The promising anti-tumor activity of these structurally novel spirocyclic compounds is reported as well.

A Facile Access to Fluorinated Pyrrolidines via Catalytic Asymmetric 1,3-Dipolar Cycloaddition of Azomethine Ylides with Methyl a-Fluoroacrylate

Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stereogenic cen- ters has been achieved with Cu（CH3CN）4BF4/TF-BiphamPhos complexes for the first time. This catalytic system performs well over a broad scope of substrates, providing the synthetically useful adducts in good yields and excel- lent diastereoselectivities and good to high enantioselectivities.

Preparation of Indolizine by Intramolecular 1,5-Dipolar Cycloaddition of Pyridinium N-Allylides

ＰｒｅｐａｒａｔｉｏｎｏｆＩｎｄｏｌｉｚｉｎｅｂｙＩｎｔｒａｍｏｌｅｃｕｌａｒ１，５┐ＤｉｐｏｌａｒＣｙｃｌｏａｄｄｉｔｉｏｎｏｆＰｙｒｉｄｉｎｉｕｍＮ┐Ａｌｙｌｉｄｅｓ＊ＺＨＯＵＪｉａｎ，ＨＵＹｕｅ－ｆｅｉ＊＊ａｎｄＨＵＨｏｎｇ－ｗｅｎ（Ｄｅｐａｒ...

Solvent-free 1,3-Dipolar Cycloaddition of Azomethine Imines with Terminal Alkynes Promoted by Calcium Fluoride Under the Ball Milling Condition

A convenient and efficient procedure for the synthesis ofN, N-bicyclic pyrazolidinone derivatives has been developed via the reaction of azomethine imines with terminal alkynes under the ball milling condition without sol- vent, which was promoted by calcium fluoride with a catalyst of copper（I） salt. The cyclization reactions exhibited moderate to high yields.

The Cycloaddition Reaction of Lawesson's Reagent with 1,3-Dienes

Lawesson's reagent undergoes [2 + 4] cycloaddition reaction with 2-methyl-1, 3-butadiene,cyclopentadiene to yield heterocycles 4 and 5, respectively.