A FACILE METHOD FOR THE CONVERSION OF OXIMES AND TOSYLHYDRAZONES TO CARBONYL COMPOUNDS WITH CR-MCM-41 ZEOLITE UNDER MICROWAVE IRRADIATION*
摘要:
Cr-MCM-41 zeolite supported on silica gel can be used as an effective and mild oxidizing agent for the direct conversion of oximes and tosylhydrazones to carbonyl compounds under microwave irradiation in good yield. The procedure is applicable to the variety of oximes and tosylhydrazones and the zeolite can be recycled.
Saturated aldehydes and ketones are converted via their p-toluenesulfonyl hydrazones to the corresponding alkanes using dichloro bis(1,4-diazabicydo[2.2.2]octane)(tetrahydroborato) zirconium(IV) (ZrBDC). The reactions were performed in DMF-sulfolane at 110 °C and gave the corresponding alkanes in high yields. Regioselectivity in the reduction of α,β-unsaturated carbonyl groups was also observed.
Alkylation of Aldehyde (Arenesulfonyl)hydrazones with Trialkylboranes
作者:George W. Kabalka、John T. Maddox、Ekaterini Bogas、Shane W. Kelley
DOI:10.1021/jo962089q
日期:1997.5.1
(Arenesulfonyl)hydrazone derivatives of aryl aldehydes are readily alkylated by trialkylboranes in the presence of base to generate new organoboranes that may be converted to the corresponding substituted alkanes or alcohols depending upon the reaction conditions chosen. Both tosyl- and trisylhydrazone derivatives can be utilized in the reaction, which tolerates a variety of functional groups, making it a versatile alternative to both the Grignard and Suzuki-coupling reactions.
Wittig Ylide Mediated Decomposition of <i>N</i>-Sulfonylhydrazones to Sulfinates
作者:Deepika Choudhary、Vineeta Khatri、Ashok K. Basak
DOI:10.1021/acs.orglett.7b03953
日期:2018.4.6
N-Sulfonylhydrazones generate sulfinates selectively when treated with a stabilized Wittig ylide in a polar aprotic solvent at elevated temperature. The transition metal and base free decomposition method is applicable to N-sulfonylhydrazones generated from a number of aromatic and heteroaromatic aldehydes and ketones. In the case of N-tosylhydrazones derived from O-allyl and O-propargyl salicylaldehydes
A Transition-Metal-Free and Base-Mediated Carbene Insertion into Sulfur-Sulfur and Selenium-Selenium Bonds: An Easy Access to Thio- and Selenoacetals
作者:Dhanarajan Arunprasath、Govindasamy Sekar
DOI:10.1002/adsc.201600855
日期:2017.2.20
A transition‐metal‐free and base‐mediated carbene insertion across sulfur‐sulfur and selenium‐selenium bonds has been developed by employing N‐tosylhydrazone as a stable and safe carbene precursor. The ylide formation from carbene followed by Stevens rearrangement are considered to be the key steps. This thiol and selenol‐free protocol delivers thioacetals and selenoacetals in good to excellent yields
Design and Application of New Imidazolylsulfonate-Based Benzyne Precursor: An Efficient Triflate Alternative
作者:Szabolcs Kovács、Ádám I. Csincsi、Tibor Zs. Nagy、Sándor Boros、Géza Timári、Zoltán Novák
DOI:10.1021/ol300529j
日期:2012.4.20
cycloadditions involving benzyne intermediates. The precursor offers an efficient alternative for generating benzynes compared to widely used ortho TMS triflates under similar reaction conditions. With the utilization of this new precursor, the formation of potentially genotoxic trifluoromethanesulfonate side product is eliminated. The applicability of the new benzyneprecursor was demonstrated in different