6926-47-2Relevant academic research and scientific papers
Alkylphosphinites as Synthons for Stabilized Carbocations
Ochmann, Lukas,Kessler, Mika L.,Schreiner, Peter R.
supporting information, p. 1460 - 1464 (2022/03/01)
We present a new acid-free method for the generation of carbocations based on a redox condensation reaction that enables SN1 reactions with a variety of nucleophiles. We utilize readily synthesized phosphinites that are activated by diisopropyl azodicarboxylate to form betaine structures that collapse upon adding a pronucleophile, thereby yielding reactive carbocation intermediates. We also employ this approach for the alkylation of some bioactive molecules.
Direct AlCl3-catalyzed transformation of benzyl THP ethers and allyl benzyl ethers
Bui, Tien Tan,Kim, Hee-Kwon
, p. 388 - 397 (2020/10/15)
THP and allyl groups are frequently used for the protection of alcohols. In this study, novel direct transformations of benzyl THP ethers and allyl benzyl ethers, protected forms of alcohols, are reported. TMSN3 and AlCl3 were employ
One-Pot Deoxygenation and Substitution of Alcohols Mediated by Sulfuryl Fluoride
Epifanov, Maxim,Mo, Jia Yi,Dubois, Rudy,Yu, Hao,Sammis, Glenn M.
, p. 3768 - 3777 (2021/03/01)
Sulfuryl fluoride is a valuable reagent for the one-pot activation and derivatization of aliphatic alcohols, but the highly reactive alkyl fluorosulfate intermediates limit both the types of reactions that can be accessed as well as the scope. Herein, we report the SO2F2-mediated alcohol substitution and deoxygenation method that relies on the conversion of fluorosulfates to alkyl halide intermediates. This strategy allows the expansion of SO2F2-mediated one-pot processes to include radical reactions, where the alkyl halides can also be exploited in the one-pot deoxygenation of primary alcohols under mild conditions (52-95% yield). This strategy can also enhance the scope of substitutions to nucleophiles that are previously incompatible with one-pot SO2F2-mediated alcohol activation and enables substitution of primary and secondary alcohols in 54-95% yield. Chiral secondary alcohols undergo a highly stereospecific (90-98% ee) double nucleophilic displacement with an overall retention of configuration.
Synthesis of 1-Pyrroline by Denitrogenative Ring Expansion of Cyclobutyl Azides under Thermal Conditions
Ban, Kazuho,Miki, Yuya,Sajiki, Hironao,Sawama, Yoshinari,Tomita, Naohito
supporting information, p. 3481 - 3484 (2021/06/17)
We herein report an efficient and systematic synthesis of 1-pyrrolines from cyclobutyl azides under thermal and neutral conditions. The reaction proceeded without any additional reagents, and nitrogen was generated as the sole by-product. Furthermore, the generated 1-pyrrolines could be continuously transformed into pyrroles, N-Boc-amines, and oxaziridines in an one-pot manner. (Figure presented.).
Facile Direct Coupling Reactions of MOM-protected Benzylic Alcohols Using Aluminum Chloride
Bui, Tien Tan,Kim, Hee-Kwon
supporting information, p. 1195 - 1198 (2021/08/03)
MOM group is one of the most commonly used protecting groups for alcohols. This study describes novel direct functionalization of the MOM-protected benzylic alcohols. Preparation of allylic compounds from benzyl MOM ethers was successfully achieved by utilization of allyltrimethylsilane and AlCl3. In addition, direct azidation of benzyl MOM ethers using TMSN3 was successful carried out under AlCl3-mediated reaction conditions. These results demonstrate that this novel synthetic procedure is a promising approach to direct functionalization of MOM-protected alcohols including allylation and azidation.
Site-Selective Copper-Catalyzed Azidation of Benzylic C-H Bonds
Suh, Sung-Eun,Chen, Si-Jie,Mandal, Mukunda,Guzei, Ilia A.,Cramer, Christopher J.,Stahl, Shannon S.
supporting information, p. 11388 - 11393 (2020/07/21)
Site selectivity represents a key challenge for non-directed C-H functionalization, even when the C-H bond is intrinsically reactive. Here, we report a copper-catalyzed method for benzylic C-H azidation of diverse molecules. Experimental and density functional theory studies suggest the benzyl radical reacts with a CuII-azide species via a radical-polar crossover pathway. Comparison of this method with other C-H azidation methods highlights its unique site selectivity, and conversions of the benzyl azide products into amine, triazole, tetrazole, and pyrrole functional groups highlight the broad utility of this method for target molecule synthesis and medicinal chemistry.
Chemo- And regioselective click reactions through nickel-catalyzed azide-alkyne cycloaddition
Baek, Seung-Yeol,Baik, Mu-Hyun,Choe, Wonyoung,Hong, Sung You,Jeon, Ji Hwan,Jeong, Seo Yeong,Kim, Woo Gyum,Nam, Dongsik
supporting information, p. 3374 - 3381 (2020/05/14)
Metal-catalyzed cycloaddition is an expeditious synthetic route to functionalized heterocyclic frameworks. However, achieving reactivity-controlled metal-catalyzed azide-alkyne cycloadditions from competing internal alkynes has been challenging. Herein, we report a nickel-catalyzed [3 + 2] cycloaddition of unsymmetrical alkynes with organic azides to afford functionalized 1,2,3-triazoles with excellent regio- and chemoselectivity control. Terminal alkynes and cyanoalkynes afford 1,5-disubstituted triazoles and 1,4,5-trisubstituted triazoles bearing a 4-cyano substituent, respectively. Thioalkynes and ynamides exhibit inverse regioselectivity compared with terminal alkynes and cyanoalkynes, affording 1,4,5-trisubstituted triazoles with 5-thiol and 5-amide substituents, respectively. Density functional theory calculations are performed for the elucidation of the reaction mechanism. The computed mechanism suggests that a nickellacyclopropene intermediate is generated by the oxidative addition of the alkyne substrate to the Ni(0)-Xantphos catalyst, and the subsequent C-N coupling of this intermediate with an azide is responsible for the chemo- and regioselectivity.
A Direct Br?nsted Acid-Catalyzed Azidation of Benzhydrols and Carbohydrates
Regier, Jeffery,Maillet, Robert,Bolshan, Yuri
, p. 2390 - 2396 (2019/04/14)
Benzhydryl alcohols were converted into their corresponding diarylazidomethane analogues using azidotrimethylsilane (TMSN3) in the presence of a catalytic amount of a Br?nsted acid HBF4·OEt2. The azidation reactions proceeded in high yields and demonstrated excellent functional group tolerance to electron-donating and electron-withdrawing substituents. In addition, a range of unprotected functional groups including amine, amide, aldehyde and alcohol were well-tolerated. Furthermore, this methodology was successfully applied to carbohydrates for the preparation of the corresponding azide derivatives.
I2/Li2CO3-promoted cyanation of diarylalcohols through a dual activation process
Hu, Liangzhen,Hussain, Muhammad Ijaz,Deng, Qingfu,Liu, Qing,Feng, Yangyang,Zhang, Xiaohui,Xiong, Yan
, p. 308 - 314 (2018/12/11)
One-step base promoted strategy for cyanation of α,α-diaryl alcohols has been developed under mild and transition metal-free conditions. This method provides a straightforward and facile way towards the synthesis of β,γ-unsaturated nitriles and α-phenylnitiriles from α-vinyl carbinols and α,α-diaryl methanols, respectively, up to 99% yield. Moreover, various azides and ethers could also be accessed from their respective nucleophiles under standard reaction conditions.
Optimal Destabilization of DNA Double Strands by Single-Nucleobase Caging
Seyfried, Patrick,Heinz, Marcel,Pintér, Gy?rgy,Kl?tzner, Dean-Paulos,Becker, Yvonne,Bolte, Michael,Jonker, Hendrik R. A.,Stelzl, Lukas S.,Hummer, Gerhard,Schwalbe, Harald,Heckel, Alexander
supporting information, p. 17568 - 17576 (2018/11/10)
Photolabile protecting groups are widely used to trigger oligonucleotide activity. The ON/OFF-amplitude is a critical parameter. An experimental setup has been developed to identify protecting group derivatives with superior caging properties. Bulky rests
