Influence of the Sulfinyl Group on the Chemoselectivity and π-Facial Selectivity of Diels−Alder Reactions of (S)-2-(p-Tolylsulfinyl)-1,4-benzoquinone
摘要:
Diels-Alder reactions of (S)-2-(p-tolylsulfinyl)-1,4-benzoquinone (1a) with cyclic (cyclopentadiene and cyclohexadiene) and acyclic dienes (1-[(trimethylsilyl)oxy]-1,3-butadiene and trans-piperylene) under different thermal and Lewis acid conditions are reported. Chemoselectivity (reactions on C-2-C-3 versus C-5-C-6 double bonds) is mainly related to the cyclic (on C-5-C-6) or acyclic (on C-2-C-3) structure of the diene. The high pi-facial selectivity observed could be controlled by choosing adequate experimental conditions.
Copper and triphenylphosphine-promoted sulfenylation of quinones with arylsulfonyl chlorides
作者:Xiaoli Yu、Qiujin Wu、Huida Wan、Zhaojun Xu、Xingle Xu、Dawei Wang
DOI:10.1039/c6ra11301j
日期:——
The efficient copper and triphenylphosphine-promoted sulfenylation of quinones with arylsulfonyl chlorides has been developed under mild conditions with moderate to good yields. Significantly, this provides an alternative method to synthesise arylthioquinone derivatives. This is the first time that arylthioquinones with arylsulfonyl chlorides as starting material have been prepared, which avoids the
Oxidative radical coupling of hydroquinones and thiols using chromic acid: one-pot synthesis of quinonyl alkyl/aryl thioethers
作者:T. P. Adarsh Krishna、Sakthivel Pandaram、Suresh Chinnasamy、Andivelu Ilangovan
DOI:10.1039/d0ra01519a
日期:——
An efficient, simple and practical protocol for one-pot sequential oxidative radical C–H/S–H cross-coupling of thiols with hydroquinones (HQs) and oxidation leading to the formation of quinonyl alkyl/aryl thioethers using H2CrO4 was developed. This cross-coupling of thiyl and aryl radicals offers mono thioethers in good to moderate yield and works well with a wide variety of thiols. Similarly, this
The convenient synthesis and reaction of 2-(arylthio)phenols under ligand-free conditions: arylthioquinone preparation through cascade C–H functionalization and oxidation from arylthiols and aryl iodides
作者:Dawei Wang、Xiaoli Yu、Likui Wang、Wei Yao、Zhaojun Xu、Huida Wan
DOI:10.1016/j.tetlet.2016.10.028
日期:2016.11
A convenient and simple method for copper-catalyzed synthesis of 2-(arylthio)phenols through C–H functionalization of arylthiols and aryl iodides was developed under ligand-free conditions without nitrogen protection. In addition, arylthioquinone derivatives were very easily prepared for one more step of oxidation with moderate to good yields. This provide an alternative and efficient way to 2-(arylthio)phenols
Chemoselective method for the synthesis of 4-allyl-4-hydroxycyclohexa-2,5-dienone derivatives from 1,4-quinones by an indium-mediated allylation protocol
作者:Dipanjan Pan、Sajal K Mal、Gandhi K Kar、Jayanta K Ray
DOI:10.1016/s0040-4020(02)00133-3
日期:2002.4
Allyl indium halide on reaction with 1,4-quinones produced 4-allyl-4-hydroxycyclohexa-2,5-dienone derivatives. Unsymmetrical quinones show high chemoselectivity in addition of allyl indium halide reagent to the carbonyl group.
Oxidation reactions using sodium metaperiodate supported on silica gel
作者:Dharmendra N. Gupta、Philip Hodge、J. Eric Davies
DOI:10.1039/p19810002970
日期:——
were stirred with sodium metaperiodiate supported on silica gel. The supported reagent was prepared by evaporating to dryness an aqueous solution of sodium metaperiodate in the presence of silica gel, followed by heating at 120 °C in vacuo. The reagent appears to consist mainly of a monomolecular layer of sodium metaperiodate bound to the silica gel by the surface hydroxy-groups, together with a minor