Aliphatic Radical Relay Heck Reaction at Unactivated C(sp3)–H Sites of Alcohols

2018 ◽  
Author(s):  
Padon Chuentragool ◽  
Dongari Yadagiri ◽  
Taiki Morita ◽  
Sumon Sarkar ◽  
Marvin Parasram ◽  
...  

<div>The Mizoroki−Heck reaction is one of the most efficient methods for alkenylation of</div><div>aryl, vinyl, and alkyl halides. Due to its innate nature, this protocol requires the employment of compounds possessing a halogen atom at the site of functionalization. However, the accessibility of organic molecules possessing a halogen atom at a particular site in aliphatic systems is extremely limited. Thus, a protocol that would allow a Heck reaction to occur at a specific non-functionalized C(sp3)−H site would be highly desirable.</div><div>Here, we report a radical relay Heck reaction which allows for a selective remote</div>alkenylation of aliphatic alcohols at unactivated β-, γ- and δ-C(sp3 20 )–H sites. The use of easily installable/removable Si-based auxiliary enables selective I-atom/radical translocation events at remote C−H sites followed by the Heck reaction. Notably, the reaction proceeds smoothly under mild visible light-mediated conditions at room temperature, producing highly modifiable and valuable alkenol products from readily available alcohols feedstocks. <br>

2018 ◽  
Author(s):  
Padon Chuentragool ◽  
Dongari Yadagiri ◽  
Taiki Morita ◽  
Sumon Sarkar ◽  
Marvin Parasram ◽  
...  

<div>The Mizoroki−Heck reaction is one of the most efficient methods for alkenylation of</div><div>aryl, vinyl, and alkyl halides. Due to its innate nature, this protocol requires the employment of compounds possessing a halogen atom at the site of functionalization. However, the accessibility of organic molecules possessing a halogen atom at a particular site in aliphatic systems is extremely limited. Thus, a protocol that would allow a Heck reaction to occur at a specific non-functionalized C(sp3)−H site would be highly desirable.</div><div>Here, we report a radical relay Heck reaction which allows for a selective remote</div>alkenylation of aliphatic alcohols at unactivated β-, γ- and δ-C(sp3 20 )–H sites. The use of easily installable/removable Si-based auxiliary enables selective I-atom/radical translocation events at remote C−H sites followed by the Heck reaction. Notably, the reaction proceeds smoothly under mild visible light-mediated conditions at room temperature, producing highly modifiable and valuable alkenol products from readily available alcohols feedstocks. <br>


2017 ◽  
Vol 129 (45) ◽  
pp. 14400-14404 ◽  
Author(s):  
Daria Kurandina ◽  
Marvin Parasram ◽  
Vladimir Gevorgyan

2020 ◽  
Vol 73 (3) ◽  
pp. 189
Author(s):  
Theerada Seehamongkol ◽  
Tyra H. Horngren ◽  
Mohammed A. M. Alhajji ◽  
Joshua Almond-Thynne ◽  
Milena L. Czyz ◽  
...  

A methodology for a radical Pictet–Spengler reaction promoted by visible light photoredox catalysis is described. This strategy furnishes tetrahydroisoquinoline derivatives bearing electron poor and electron rich substituents. The reaction proceeds at room temperature and with excellent regioselectivity for the 6-endo intramolecular cyclisation. This radical approach provides a complementary method for the synthesis of the tetrahydroisoquinoline scaffold with substitution patterns inaccessible via established thermal transformations.


2019 ◽  
Vol 10 (4) ◽  
pp. 976-982 ◽  
Author(s):  
Jianyang Dong ◽  
Xueli Lyu ◽  
Zhen Wang ◽  
Xiaochen Wang ◽  
Hongjian Song ◽  
...  

Herein, we report a protocol for direct visible-light-mediated Minisci C–H alkylation of heteroarenes with unactivated alkyl halides using molecular oxygen as an oxidant at room temperature.


Synthesis ◽  
2021 ◽  
Author(s):  
Amit banerjee ◽  
Tomohiro Hattori ◽  
Hisashi Yamamoto

Bimolecular nucleophilic substitution (S N 2) is one of the most known fundamental reactions in organic chemistry to generate new molecules from two molecules. In principle, a nucleophile attacks from the back side of an alkylating agent having a suitable leaving group, most commonly using a halide. However, alkyl halides are expensive, very harmful, toxic and not so stable which makes them problematic for laboratory use. In contrast, trialkyl phosphates are cheap, readily accessible, stable at room temperature, under air, and are easy to handle but rarely used as alkylating agents in organic synthesis. Here, we describe a mild, straightforward and powerful method for nucleophilic alkylation of various nucleophiles such as N-, O-, C- and S- using readily available trialkyl phosphate. The reaction proceeds smoothly with excellent yield and quantitative yield in many cases and covers a wide range of substrates. Further, the rare stereoselective transfer of secondary alkyl groups has been achieved with inversion of configuration of chiral centers (up to >99% ee).


2020 ◽  
Vol 22 (10) ◽  
pp. 3964-3968 ◽  
Author(s):  
Liyan Feng ◽  
Lin Guo ◽  
Chao Yang ◽  
Jia Zhou ◽  
Wujiong Xia

Synthesis ◽  
2019 ◽  
Vol 52 (02) ◽  
pp. 219-226 ◽  
Author(s):  
Ce Liang ◽  
Wang-Tao Zhuo ◽  
Yan-Ning Niu ◽  
Guo-Lin Gao

A photoredox catalytic strategy has been described for the direct C2 trifluoromethylation of quinoline N-oxides. This reaction is compatible with a range of synthetically relevant functional groups for providing efficient synthesis of a variety of C2 trifluoromethyl quinoline N-oxides at room temperature. Mechanistic studies indicated that the reaction proceeds via a radical pathway.


Author(s):  
Polyssena Renzi ◽  
Emanuele Azzi ◽  
Enrico Bessone ◽  
Giovanni Ghigo ◽  
Stefano Parisotto ◽  
...  

An unprecedented visible light enhanced room temperature Heck reaction between aryl halides and allenyl tosyl amines is here reported. The simple catalytic system (Pd(OAc)2/PPh3) is exploited to afford arylated vinyl...


1998 ◽  
Vol 536 ◽  
Author(s):  
N. Y. Kim ◽  
P. E. Laibinis

AbstractThis paper describes the covalent attachment of various organic molecules to the hydrogenterminated surface of porous silicon using alcohols and Grignard reagents. With alcohols, the chemical reaction forms Si-O-C attachments to the silicon substrate and requires modest heating (40–70 °C). With Grignard reagents, the reaction proceeds at room temperature and forms a covalent film that is attached by Si-C bonds to the silicon support. Evidence for these reactions is provided by infrared and x-ray photoelectron spectroscopies.


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