189368-12-5Relevant academic research and scientific papers
Palladium-catalyzed difunctionalization of internal alkynes via highly regioselective 6- endo cyclization and alkenylation of enynoates: Synthesis of multisubstituted pyrones
Tian, Pan-Pan,Cai, Sai-Hu,Liang, Qiu-Ju,Zhou, Xing-Yi,Xu, Yun-He,Loh, Teck-Peng
, p. 1636 - 1639 (2015)
An efficient Pd(II)-catalyzed difunctionalization reaction of internal alkynes is reported. In this reaction, various enynoates and electron-deficient alkenes were used for the syntheses of useful highly substituted pyrone derivatives via a 6-endo cycliza
Fe(III)-Catalyzed, Cyclizative Coupling between 2-Alkynylbenzoates and Carbinols: Rapid Generation of Polycyclic Isocoumarins and Phthalides and Mechanistic Study
Gandhi, Soniya,Baire, Beeraiah
supporting information, p. 2651 - 2657 (2020/05/25)
FeCl3 catalyzed, highly regioselective cyclizative coupling of internal alkynes with alcohols has been reported for the rapid synthesis of structurally divergent, complex isocoumarins and phthalides respectively in intermolecular and intramolecular fashion. This strategy exhibited very high substrate scope and efficiency and proceeds through the simultaneous formation of C?O and C?C bonds. Observations from a series of control experiments supported a) the mechanism as Lewis acid catalyzed dual activation of ester and alcohol, b) the role of carbocation for the enhanced rates of cyclization, i. e., activation of alkyne by carbocation, and c) no role of HCl in the reported cascade process. (Figure presented.).
Essential structural features of (2Z,4E)-5-phenylpenta-2,4-dienoic acid for inhibition of root gravitropism
Shindo, Mitsuru,Makigawa, Saki,Matsumoto, Kenji,Iwata, Takayuki,Wasano, Naoya,Kano, Arihiro,Morita, Miyo Terao,Fujii, Yoshiharu
, (2020/02/04)
Previously, we found (2Z,4E)-5-phenylpenta-2,4-dienoic acid (ku-76) to be a selective inhibitor of root gravitropic bending of lettuce radicles at 5 μM, with no concomitant growth inhibition. Here, we describe a structure-activity relationship study of ku
In Situ Generation of Alkynylzinc and Its Subsequent Negishi Reaction in a Flow Reactor
Kandasamy, Mohanraj,Huang, Yu- Hsuan,Ganesan, Balaji,Senadi, Gopal Chandru,Lin, Wei-Yu
, p. 4349 - 4356 (2019/07/03)
A highly efficient and convenient Negishi cross-coupling reaction has been developed for the synthesis of unsymmetrical alkynes and enynes in a continuous-flow process. The reaction proceeds through an in situ generated alkynylzinc reagent by the reaction of lithium acetylide with zinc halide at room temperature followed by a cross-coupling reaction with aryl or vinyl iodides. The notable features of this work compared to the conventional benchtop method are mild reaction conditions, good to excellent yields, broad functional-group compatibility, short residence time (73 sec) and especially desilylation of TMS group with the residence time of only 10.5 sec.
Palladium-Catalyzed One-Pot Highly Regioselective 6- Endo Cyclization and Alkylation of Enynoates: Synthesis of 2-Alkanone Pyrones
Ahmad, Tanveer,Qiu, Sheng-Qi,Xu, Yun-He,Loh, Teck-Peng
, p. 13414 - 13426 (2018/11/02)
The Pd(II)-catalyzed one-pot tandem cyclization/alkylation reactions of enynoates with allylic alcohols have been demonstrated. In this reaction, an innovative protocol proceeded well through Pd-catalyzed intramolecular selective 6-endo cyclization, inser
Facile synthesis of α, β-unsaturated esters through a one-pot copper-catalyzed aerobic oxidation-Wittig reaction
Ren, Cheng,Shi, Zhenyu,Ding, Weijie,Liu, Zhiqing,Jin, Huile,Yu, Xiaochun,Wang, Shun
supporting information, p. 14 - 17 (2017/12/06)
An efficient one-pot synthesis of α, β-unsaturated esters through the aerobic oxidation – Wittig tandem reaction of alcohols and phosphorous ylide is developed. This new method operates under mild reaction conditions, and uses CuI/TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) as co-catalyst and air (O2) as the oxidant. It tolerates a wide range of functionalized benzylic alcohol and aliphatic alcohols.
Palladium-catalyzed convenient one-pot synthesis of multi-substituted 2-pyrones via transesterification and alkenylation of enynoates
Pathare, Ramdas S.,Sharma, Shivani,Gopal, Kandasamy,Sawant, Devesh M.,Pardasani, Ram T.
supporting information, p. 1387 - 1389 (2017/03/17)
An efficient one-pot protocol for the synthesis of multi-substituted 2-pyrone derivatives from internal alkynes and unactivated alkenes is reported. The methodology involves difunctionalization of internal alkynes by using Pd(II) as a catalyst alongwith X-Phos as ligand via 6-endo transesterification and subsequent alkenylation pathway. Notable features include simple and easily available starting materials, including a range of unactivated alkenes, reduced synthetic steps and mild reaction conditions with high efficiency.
Catalyst-Free Synthesis of Borylated Lactones from Esters via Electrophilic Oxyboration
Faizi, Darius J.,Issaian, Adena,Davis, Ashlee J.,Blum, Suzanne A.
supporting information, p. 2126 - 2129 (2016/03/05)
A catalyst-free oxyboration reaction of alkynes is developed. The resulting borylated isocoumarins and 2-pyrones are isolated as boronic acids, pinacolboronate esters, or potassium organotrifluoroborate salts, providing a variety of bench-stable organobor
Synthesis of Highly Substituted Racemic and Enantioenriched Allenylsilanes via Copper-Catalyzed Hydrosilylation of (Z)-2-Alken-4-ynoates with Silylboronate
Wang, Min,Liu, Zheng-Li,Zhang, Xiang,Tian, Pan-Pan,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 14830 - 14833 (2015/12/08)
Copper-catalyzed highly efficient hydrosilylation reaction of enynoates was developed. Under simple reaction conditions, various di-, tri-, and tetrasubstituted racemic allene products could be obtained in high yields. The asymmetric 1,6-addition of silyl group to the (Z)-2-alken-4-ynoates could be achieved under mild reaction conditions to afford the silyl-substituted enantioenriched chiral allene products in good yields and with high enantioselectivities.
OMS-2 for aerobic, catalytic, one-pot alcohol oxidation-wittig reactions: Efficient access to α,β-unsaturated esters
Kona, Jagadeswara R.,King'Ondu, Cecil K.,Howell, Amy R.,Suib, Steven L.
, p. 749 - 752 (2014/03/21)
Manganese oxide octahedral molecular sieve (OMS) materials with well-defined pores have been extensively studied over two decades due to their intriguing chemical and physical properties. OMS-2, the synthetic cryptomelane form of manganese oxide, was synthesized by a modified reflux method and was found to be highly active for obtaining α,β-unsaturated esters (up to 95 % yield and with high diastereoselectivities) from a variety of benzyl, heteroaryl, allyl and alkyl alcohols via one-pot alcohol oxidation-Wittig reaction. The transformation utilizes air as the stoichiometric oxidant, and the inexpensive catalyst can be recovered and reused. Filter and use again! Porous manganese oxide molecular sieve based catalysts were found to efficiently promote the oxidation of a variety of alcohols to the aldehydes, which reacted insitu with stabilized Wittig reagent, providing almost exclusively E-α,β-unsaturated esters in good to excellent yields. The heterogeneous catalyst used was made from inexpensive starting materials, and the recovered catalyst was found to be reusable with a modest loss in activity.
