1486517-18-3Relevant academic research and scientific papers
Electrochemical Semipinacol Rearrangements of Allylic Alcohols: Construction of All-Carbon Quaternary Stereocenters
Kang, Jun-Chen,Tu, Yong-Qiang,Dong, Jia-Wei,Chen, Chao,Zhou, Jia,Ding, Tong-Mei,Zai, Jian-Tao,Chen, Zhi-Min,Zhang, Shu-Yu
supporting information, p. 2536 - 2540 (2019/04/30)
The first examples of electrochemical trifluoromethylation and sulfonylation/semipinacol rearrangements of allylic alcohols were developed using cheap and stable RSO2Na (R = CF3, Ph) as reagents. Various β-trifluoromethyl and sulfonated ketones were obtained in moderate to excellent yields. This strategy provides a facile, direct, and complementary approach to construct all-carbon quaternary stereocenters. In addition, the reaction has the advantages of being chemical oxidant-free and metal-free and has safe and mild reaction conditions.
Cyclic Hypervalent Iodine Reagents for Azidation: Safer Reagents and Photoredox-Catalyzed Ring Expansion
Alazet, Sebastien,Preindl, Johannes,Simonet-Davin, Raphael,Nicolai, Stefano,Nanchen, Annik,Meyer, Thierry,Waser, Jerome
, p. 12334 - 12356 (2018/09/27)
Azides are building blocks of increasing importance in synthetic chemistry, chemical biology, and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its hazardous nature. We introduce two derivatives, tBu-ABX and ABZ (azidobenziodazolone), with a better safety profile, and use them in established photoredox- and metal-mediated azidations, and in a new ring-expansion of silylated cyclobutanols to give azidated cyclopentanones.
Enantioselective halogenative semi-pinacol rearrangement: Extension of substrate scope and mechanistic investigations
Romanov-Michailidis, Fedor,Romanova-Michaelides, Maria,Pupier, Marion,Alexakis, Alexandre
supporting information, p. 5561 - 5583 (2015/03/30)
The present Full Paper article discloses a survey of our recent results obtained in the context of the enantioselective halogenation-initiated semi-pinacol rearrangement. Commencing with the fluorination/semi-pinacol reaction first and moving to the heavier halogens (bromine and iodine) second, the scope and limitations of the halogenative phase-transfer methodology will be discussed and compared. An extension of the fluorination/semi-pinacol reaction to the ring-expansion of five-membered allylic cyclopentanols will be also described, as well as some preliminary results on substrates prone to desymmetrization will be given. Finally, the present manuscript will culminate with a detailed mechanistic investigation of the canonical fluorination/semi-pinacol reaction. Our mechanistic discussion will be based on in situ reaction progress monitoring, complemented with substituent effect, kinetic isotopic effect and non-linear behaviour studies.
Asymmetric chlorination/ring expansion for the synthesis of α-quaternary cycloalkanones
Yin, Qin,You, Shu-Li
supporting information, p. 1810 - 1813 (2014/04/17)
A highly enantioselective chlorination/ring expansion cascade for the construction of cycloalkanones with an all-carbon quaternary center was realized (up to 97% ee). Oxa-cyclobutanol substrates were employed for the first time in the ring expansion reactions, affording the functionalized dihydrofuranones in excellent enantioselectivity.
Enantioselective organocatalytic fluorination-induced Wagner-Meerwein rearrangement
Romanov-Michailidis, Fedor,Guénée, Laure,Alexakis, Alexandre
supporting information, p. 9266 - 9270 (2013/09/12)
Cracked under strain: Strained allylic cyclobutanols and cyclopropanols readily undergo a ring expansion described by the title rearrangement. This reaction is promoted by catalytic amounts of 1 and displays high tolerance with respect to the substrate scope. The corresponding β-fluoro spiroketone products are isolated in high yields and with excellent stereoselectivities. EDG=electron-donating group, EWG=electron-withdrawing group. Copyright
Enantioselective organocatalytic iodination-initiated Wagner-Meerwein rearrangement
Romanov-Michailidis, Fedor,Guenee, Laure,Alexakis, Alexandre
supporting information, p. 5890 - 5893 (2013/12/04)
The present manuscript describes a high-yielding enantioselective semipinacol transposition, initiated by an electrophilic iodination event. The title transformation makes use of the anionic phase-transfer catalysis (PTC) paradigm for chirality induction. Thus, when combined appropriately, the insoluble cationic iodinating reagent S9 and the lipophilic phosphoric acid L9 act as an efficient source of chiral iodine that performs the semipinacol transposition of strained allylic alcohols A x to β-iodo spiroketones Bx in good yields and with high levels of diastereo- and enantio-induction. The product β-iodo spiroketones could be derivatized stereospecifically and without stereoerosion, giving rise to products inaccessible directly from a semipinacol rearrangement.
