210964-22-0Relevant articles and documents
Studies on tellurium-containing heterocycles. Part 18. Preparation and structure of 2-benzotelluropyrylium salts and 2-benzoselenopyrylium salts
Sashida, Haruki,Ohyanagi, Kazuo,Minoura, Mao,Akiba, Kin-Ya
, p. 606 - 612 (2002)
The regioselective and stereospecific intramolecular ring closure reactions of o-ethynylbenzyl tellurols 5A and o-ethynylbenzyl selenols 5B, which were readily generated by the reaction of the o-ethynylbenzyl bromides 4 with sodium hydrogen telluride (NaH
Fused-Ring Formation by an Intramolecular “Cut-and-Sew” Reaction between Cyclobutanones and Alkynes
Deng, Lin,Jin, Likun,Dong, Guangbin
supporting information, p. 2702 - 2706 (2018/02/12)
The development of a catalytic intramolecular “cut-and-sew” transformation between cyclobutanones and alkynes to construct cyclohexenone-fused rings is described herein. The challenge arises from the need for selective coupling at the more sterically hind
A simple and mild synthesis of 1H-isochromenes and (Z)-1-alkylidene-1,3- dihydroisobenzofurans by the iodocyclization of 2-(1-alkynyl)benzylic alcohols
Mancuso, Raffaella,Mehta, Saurabh,Gabriele, Bartolo,Salerno, Giuseppe,Jenks, William S.,Larock, Richard C.
supporting information; experimental part, p. 897 - 901 (2010/05/02)
(Chemical Equation Presented) A variety of iodo-substituted isochromenes, dihydroisobenzofurans, and pyranopyridines are readily prepared in good to excellent yields under mild conditions by the iodocyclization of readily available 2-(1-alkynyl)benzylic a
Iodine-mediated electrophilic cyclization of 2-alkynyl-1-methylene azide aromatics leading to highly substituted isoquinolines and its application to the synthesis of norchelerythrine
Fischer, Dirk,Tomeba, Hisamitsu,Pahadi, Nirmal K.,Patil, Nitin T.,Huo, Zhibao,Yamamoto, Yoshinori
supporting information; scheme or table, p. 15720 - 15725 (2009/03/12)
The reaction of 2-alkynyl-1-methylene azide aromatics 1 with iodine and/or other iodium donors, such as the Barluenga reagent (Py2IBF 4/HBF4) and NIS, gave highly substituted cyclization products, namely, the 1,3-disubstituted 4-iodoisoquinolines 2, in good to high yields. Not only simple 2-alkynyl benzyl azides 1a-j and their substituted analogues 1k-u and 6 but also heteroaromatic analogues, including pyridine 8, pyrroles 10a-c, furane 10d, and thiophenes 10e-g, gave the corresponding isoquinoline derivatives in excellent to allowable yields. Electron-donating and electron-accepting substituents on the aromatic ring were equally tolerated, and either acidic or basic (or even neutral) reaction conditions, depending on the reactivity of the substrate, could be applied to smoothly convert the azide starting materials into the desired isoquinoline products in moderate to good yields. Limits were found only in connection with the substituent at the alkyne terminus, where electron-neutral or electron-donating substituents are clearly favored. The iodine-mediated electrophilic cyclization of 1 most probably proceeds through the iodonium ion intermediate 4 followed by nucleophilic cyclization of the azide and subsequent elimination of N2. This new methodology was successfully applied to the short synthesis of norchelerythrine.
Synthesis of 1,3,4-trisubstituted isoquinolines by iodine-mediated electrophilic cyclization of 2-alkynyl benzyl azides
Fischer, Dirk,Tomeba, Hisamitsu,Pahadi, Nirmal K.,Patil, Nitin T.,Yamamoto, Yoshinori
, p. 4764 - 4766 (2008/02/10)
(Chemical Equation Presented) The I's have it: A series of 2-alkynyl benzyl azides have been smoothly converted into 1,3,4-trisubstituted isoquinolines in moderate to excellent yields by an iodonium-mediated synthesis (see scheme). Depending on the struct
Cyclization reactions of 2-alkynylbenzyl alcohol and 2-alkynylbenzylamine derivatives promoted by tetrabutylammonium fluoride
Hiroya, Kou,Jouka, Rumi,Kameda, Mitsuyoshi,Yasuhara, Akito,Sakamoto, Takao
, p. 9697 - 9710 (2007/10/03)
The regioselectivity of the cyclization reaction of 2-ethynylbenzyl alcohol and 2-ethynylbenzylamine derivatives promoted by TBAF was investigated. Six-membered ring derivatives were obtained from the compounds, which have a butyl group on the triple bond. Whereas five-membered ring products were afforded from the substrates having hydrogen or aromatic substituents on the acetylene moiety. It was also concluded that both the tetrabutylammonium cation and fluoride anion were essential for the cyclization. Thus, the actual mechanism and catalytic cycle were also suggested.
