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91.
Sankareswaran Srimurugan Paulsamy Suresh Thirukkallam Kanthadai Varadarajan 《合成通讯》2013,43(15):2483-2490
A facile method for the synthesis of (2R,3R)‐1,4‐dimethoxy‐1,1,4,4‐tetrasubstituted‐2,3‐butanediols involving oxidative cleavage of benzylidene acetal as a key step is described. These sterically hindered diols unusually formed cyclic sulfites as the major product under methanesulfonylation reaction conditions. 相似文献
92.
Sunil U. Tekale Suresh S. Shisodia Sushma S. Kauthale Vivekanand B. Jadhav Nilesh S. Kanhe Sudha V. Bhoraskar 《合成通讯》2013,43(13):1849-1858
The present work introduces for the first time the catalytic utility of micron particulate aluminium nitride (AlN/Al) as a novel and reusable heterogeneous catalyst for the synthesis of bis(indolyl)methanes involving the electrophilic substitution of indoles on aldehydes. The catalyst is recyclable and works without any significant change in its catalytic activity. 相似文献
93.
J. Jon Paul Selvam M. Srinivasulu N. Suryakiran V. Suresh S. Malla Reddy 《合成通讯》2013,43(11):1760-1767
A mild and efficient synthesis of bis(indolyl) methanes by the reaction of indoles with various aldehydes at room temperature in the presence of a catalytic amount of a La(NO3)3 · 6H2O afforded the corresponding bis(indolyl) methanes in excellent yields under solvent‐free conditions. 相似文献
94.
One-pot three component synthesis of novel pyrido[1,4]-oxazepine fused spiropyrrolidines has been accomplished in good yields by 1,3-dipolar cycloaddition reaction of azomethine ylide, derived from paraformaldehyde and sarcosine with (E)-4-benzylidene-hexahydro-1H-pyrido[2,1-c][1,4]-oxazepine-3(7H)-one as dipolarophiles derived from Baylis-Hillman adducts. The effect of solvent on the [3 + 2]-cycloaddition reaction is also studied. 相似文献
95.
Suresh B. Waghmode Ganesh Mahale Viraj P. Patil Kartik Renalson Dharmendra Singh 《合成通讯》2013,43(24):3272-3280
A rapid method for selective cleavage of aryl methylethers can be achieved in the presence of a protic acid and a catalytic amount of phase-transfer catalyst (Aliquat-336). Aliquat-336 accelerates the rate of reaction and affords the corresponding phenols in excellent to good yields on a wide variety of substrates. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
96.
An efficient superparamagnetic Pd–ZnFe2O4 solid catalyst has been synthesized by loading Pd(0) species on zinc ferrite nanoparticles. Sonogashira cross couplings between terminal alkynes and aryl halides were achieved in the absence of any Cu co-catalyst. A Heck–Matsuda coupling reaction of structurally different aryldiazonium tetrafluoroborate substrates was preceded at 40 °C in water. Cyanation of aryl halides was successfully done using K4[Fe(CN)6] as the cyanide source over Pd–ZnFe2O4. The catalyst was also employed for Ullmann type cross coupling reactions. Excellent yield of the products, reusability, and uncomplicated work-up make this catalyst efficient for C–C and C–O coupling reactions. Good yield of products, easy separation, and negligible leaching of Pd from the catalyst surface confirm the true heterogeneity in these catalytic reactions. 相似文献
97.
98.
Arghya Sadhukhan Debashis Sahu Dr. Bishwajit Ganguly Dr. Noor‐ul H. Khan Dr. Rukhsana I. Kureshy Dr. Sayed H. R. Abdi Dr. E. Suresh Dr. Hari C. Bajaj 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(42):14224-14232
A chiral oxazoline‐based organocatalyst has been found to efficiently catalyze asymmetric Strecker reactions of various aromatic and aliphatic N‐benzhydrylimines with trimethylsilyl cyanide (TMSCN) as a cyanide source at ?20 °C to give α‐aminonitriles in high yield (96 %) with excellent chiral induction (up to 98 % ee). DFT calculations have been performed to rationalize the enantioselective formation of the product with the organocatalyst in these reactions. The organocatalyst has been characterized by single‐crystal X‐ray diffraction analysis, as well as by other analytical methods. This protocol has been extended to the synthesis of the pharmaceutically important drug molecule levamisole in high yield and with high enantioselectivity. 相似文献
99.
The first stereoselective total synthesis of natural product, dendrodolide A (1) is described from readily available (R)-propylene oxide and 3-buten-1-ol as starting materials. The synthesis was achieved in 10 steps with an overall yield of 19.1%. The key steps involved in the synthesis are Jacobsen hydrolytic kinetic resolution, epoxide ring opening with 2-allyl-1, 3-dithiane, Yamaguchi esterification, and ring-closing metathesis (RCM). 相似文献
100.
Ch. Syama Sundar M. Ramana Reddy B. Sridhar S. Kiran Kumar C. Suresh Reddy B.V. Subba Reddy 《Tetrahedron letters》2014
A novel intramolecular Prins cyclization of (E)-5-(2-(hydroxymethyl)phenyl)pent-4-en-1-ol with aldehydes has been achieved using 10 mol % BF3·Et2O to produce 1-(tetrahydropyran-3-yl)-1,3-dihydroisobenzofuran derivatives in good to excellent yields with high selectivity. Similar type of coupling with salicylaldehydes provides the trans-fused hexahydropyrano[3,2-c]chromene derivatives in excellent yields. 相似文献