Synthesis of functionalized 3-isochromanones via metal-free intramolecular alkoxylation-initiated cascade cyclization

2019 ◽  
Vol 21 (11) ◽  
pp. 3023-3028 ◽  
Author(s):  
Ying-Qi Zhang ◽  
Xin-Qi Zhu ◽  
Yin Xu ◽  
Hao-Zhen Bu ◽  
Jia-Le Wang ◽  
...  
Keyword(s):  
Allyl Ether ◽  
Metal Free ◽  
Cascade Cyclization ◽  
High Yields

A metal-free intramolecular alkoxylation-initiated cascade cyclization of allyl ether-tethered ynamides has been developed, leading to functionalized 3-isochromanones in high yields.

scholarly journals Transition-metal-free allylation of 2-azaallyls with allyl ethers through polar and radical mechanisms

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guogang Deng ◽  
Shengzu Duan ◽  
Jing Wang ◽  
Zhuo Chen ◽  
Tongqi Liu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Allyl Ether ◽  
Metal Catalyst ◽  
Metal Free ◽  
Allyl Ethers ◽  
Bond Forming ◽  
Allyl Halides ◽  
Synthetic Utility ◽  
Insight Into ◽  
Allyl Esters

AbstractAllylation of nucleophiles with highly reactive electrophiles like allyl halides can be conducted without metal catalysts. Less reactive electrophiles, such as allyl esters and carbonates, usually require a transition metal catalyst to facilitate the allylation. Herein, we report a unique transition-metal-free allylation strategy with allyl ether electrophiles. Reaction of a host of allyl ethers with 2-azaallyl anions delivers valuable homoallylic amine derivatives (up to 92%), which are significant in the pharmaceutical industry. Interestingly, no deprotonative isomerization or cyclization of the products were observed. The potential synthetic utility and ease of operation is demonstrated by a gram scale telescoped preparation of a homoallylic amine. In addition, mechanistic studies provide insight into these C(sp3)–C(sp3) bond-forming reactions.

Brønsted Acid-Catalyzed Solvent-Controlled Regioselective Hydrothiolation and Diastereoselective Cascade Cyclization of Dienes

2021 ◽  
Author(s):  
Kai Ji ◽  
Ka Lu ◽  
Jie Huang ◽  
Zi-Hao Li ◽  
Tong-Mei Ding ◽  
...  
Keyword(s):  
Free Atom ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Metal Free ◽  
Cascade Cyclization ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
First Time

A highly regio- and diastereo-selective Brønsted acid-catalyzed tandem hydrothiolation/Friedel-Crafts reaction of linear 1,3-dienes has been developed for the first time, which provides a metal-free, atom-economic and concise way of constructing...

Cinchona alkaloid and di-tert-butyldicarbonate–DMAP promoted efficient synthesis of (E)-nitroolefins

RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54495-54502 ◽  
Author(s):  
Nataraj Poomathi ◽  
Paramasivan T. Perumal
Keyword(s):  
Cinchona Alkaloid ◽  
Efficient Synthesis ◽  
Metal Free ◽  
High Yields

A simple and efficient metal-free methodology for the synthesis of β-nitroolefins has been developed from arylidinemalononitrile using bifunctional cinchona alkaloid along with di-tert-butyldicarbonate–DMAP in high yields with total selectivity.

A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines

2016 ◽  
Vol 14 (34) ◽  
pp. 8026-8029 ◽  
Author(s):  
Simin Wei ◽  
Xiangqing Feng ◽  
Haifeng Du
Keyword(s):  
Metal Free ◽  
High Yields

A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines was realized to furnish the desired products in high yields with up to 42% ee.

Diverse privileged N-polycyclic skeletons accessed from a metal-free cascade cyclization reaction

2021 ◽  
Vol 19 (37) ◽  
pp. 8086-8095
Author(s):  
Wenzhong Li ◽  
Yu Wang ◽  
Huijing Qi ◽  
Ran Shi ◽  
Jiazhu Li ◽  
...  
Keyword(s):  
Membered Ring ◽  
Cyclization Reaction ◽  
One Pot ◽  
Metal Free ◽  
Cascade Cyclization ◽  
One Pot Synthesis ◽  
Ring Compounds

Metal-free cascade cyclization of 2-acylbenzoic acids with amines provided a one-pot synthesis of diverse isoindoloisoquinoline and benzoindolizinoindole derivatives, which were subsequently used to produce nitrogen-containing nine-membered ring compounds.

A Convenient Synthesis of 1,5-Fused 1,2,4-Triazoles from N-Arylamidines via Chloramine-T Mediated Intramolecular Oxidative N–N Bond Formation

Synthesis ◽  
2019 ◽  
Vol 51 (20) ◽  
pp. 3883-3890
Author(s):  
Ashish Bhatt ◽  
Rajesh K. Singh ◽  
Ravi Kant ◽  
Bhupendra K. Sarma
Keyword(s):  
Reaction Time ◽  
Bond Formation ◽  
Available N ◽  
Short Reaction Time ◽  
Metal Free ◽  
Convenient Synthesis ◽  
Chloramine T ◽  
High Yields ◽  
Short Time

A convenient synthesis of 1,5-fused 1,2,4-triazoles from readily available N-arylamidines is reported. The reaction is efficiently promoted by chloramine-T to afford the desired products mostly in high yields and in relatively short time, through direct metal-free oxidative N−N bond formation. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This protocol is effective toward various substrates having different functionalities.

Metal-free switchable ortho/ipso-cyclization of N-aryl alkynamides: divergent synthesis of 3-selenyl quinolin-2-ones and azaspiro[4,5]trienones

2019 ◽  
Vol 17 (48) ◽  
pp. 10163-10166 ◽  
Author(s):  
Harekrishna Sahoo ◽  
Gowri Sankar Grandhi ◽  
Isai Ramakrishna ◽  
Mahiuddin Baidya
Keyword(s):  
Metal Free ◽  
High Yields

A selenium radical triggered switchable ortho/ipso-cyclization cascade of N-aryl alkynamides has been devised under metal-free conditions to access 3-selenyl quinolin-2-ones and 3-selenospiro[4,5]trienones in high yields (up to 98%).

A photo-auxiliary approach – enabling excited state classical phototransformations with metal free visible light irradiation

2017 ◽  
Vol 53 (10) ◽  
pp. 1692-1695 ◽  
Author(s):  
Akila Iyer ◽  
Steffen Jockusch ◽  
Jayaraman Sivaguru
Keyword(s):  
Excited State ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Uv Light ◽  
Light Irradiation ◽  
Metal Free ◽  
High Yields

To address the problem of using UV light to initiate traditional photoreactions, hydrazide based chromophores are evaluated as a “photo-auxiliary“ with visible light using a metal free photocatalyst to afford photoproducts in high yields.

Metal-free sulfonyl radical-initiated cascade cyclization to access sulfonated indolo[1,2-a]quinolines

2019 ◽  
Vol 55 (84) ◽  
pp. 12615-12618 ◽  
Author(s):  
Kai Sun ◽  
Xiao-Lan Chen ◽  
Yin-Li Zhang ◽  
Kai Li ◽  
Xian-Qiang Huang ◽  
...  
Keyword(s):  
Cascade Reaction ◽  
Quinoline Derivatives ◽  
Metal Free ◽  
Cascade Cyclization

A metal-free cascade reaction was developed for the synthesis of indolo[1,2-a]quinoline derivatives from arylsulfonyl hydrazides and 1-(2-(arylethynyl)phenyl)indoles in the presence of TBAI/TBHP.

TFA-promoted sulfonation/cascade cyclization of 2-propynolphenols with sodium sulfinates to 4-sulfonyl 2H-chromenes under metal-free conditions

2019 ◽  
Vol 6 (17) ◽  
pp. 3162-3166 ◽  
Author(s):  
Tao Yang ◽  
Peihao Kou ◽  
Fengyan Jin ◽  
Xian-Rong Song ◽  
Jiang Bai ◽  
...  
Keyword(s):  
Metal Free ◽  
Cascade Cyclization ◽  
Mild Conditions

A novel, efficient and metal-free cascade sulfonylation/cyclization of 2-propynolphenols with commercially available sodium sulfinates was developed for the synthesis of 4-sulfonyl 2H-chromenes under mild conditions.

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