75506-74-0Relevant academic research and scientific papers
Chemoselective Oxidation of Equatorial Alcohols with N-Ligated λ3-Iodanes
Mikhael, Myriam,Adler, Sophia A.,Wengryniuk, Sarah E.
supporting information, p. 5889 - 5893 (2019/08/26)
The site-selective and chemoselective functionalization of alcohols in complex polyols remains a formidable synthetic challenge. Whereas significant advancements have been made in selective derivatization at the oxygen center, chemoselective oxidation to the corresponding carbonyls is less developed. In cyclic systems, whereas the selective oxidation of axial alcohols is well known, a complementary equatorial selective process has not yet been reported. Herein we report the utility of nitrogen-ligated (bis)cationic λ3-iodanes (N-HVIs) for alcohol oxidation and their unprecedented levels of selectivity for the oxidation of equatorial over axial alcohols. The conditions are mild, and the simple pyridine-ligated reagent (Py-HVI) is readily synthesized from commercial PhI(OAc)2 and can be either isolated or generated in situ. Conformational selectivity is demonstrated in both flexible 1,2-substituted cyclohexanols and rigid polyol scaffolds, providing chemists with a novel tool for chemoselective oxidation.
(Poly)cationic λ3-Iodane-Mediated Oxidative Ring Expansion of Secondary Alcohols
Walters, Jennifer C.,Tierno, Anthony F.,Dubin, Aimee H.,Wengryniuk, Sarah E.
, p. 1460 - 1464 (2018/04/06)
Herein, a simplified approach to the synthesis of medium-ring ethers through the electrophilic activation of secondary alcohols with (poly)cationic λ3-iodanes (N-HVIs) is reported. Excellent levels of selectivity are achieved for C–O bond migration over established α-elimination pathways, enabled by the unique reactivity of a novel 2-OMe-pyridine-ligated N-HVI. The resulting hexafluoroisopropanol (HFIP) acetals are readily derivatized with a range of nucleophiles, providing a versatile functional handle for subsequent manipulations. The utility of this methodology for late-stage natural product derivatization was also demonstrated, providing a new tool for diversity-oriented synthesis and complexity-to-diversity (CTD) efforts. Preliminary mechanistic investigations reveal a strong effect of alcohol conformation on the reactive pathway, thus providing a predictive power in the application of this approach to complex molecule synthesis.
A novel palladium-catalyzed arylation - dehydroaromatization reaction: Synthesis of 7-aryltetralones
Varseev, Georgy N.,Maier, Martin E.
, p. 3881 - 3884 (2007/10/03)
(Chemical Equation Presented) A new one-pot room-temperature palladium-catalyzed synthesis of 7-aryltetralones was discovered. This tandem process includes a palladium-catalyzed γ-selective arylation of the enone 4 followed by a dehydrogenation-aromatization of the initial cross-coupling product.
2-(3-Lithiopropyl)- and 2-(3-lithiopropyl)-2-methyl-1,3-dioxolane: New masked lithium bishomoenolates in the synthesis of bifunctionalized compounds
Ramon, Diego J.,Yus, Miguel
, p. 3763 - 3766 (2007/10/02)
2-(3-Lithiopropyl)- and 2-(3-lithiopropyl)-2-methyl-1,3-dioxolane (2) are prepaned by lithiation of the corresponding chlorinated precursors with lithium naphthalenide at -78°C. The reaction of these masked bishomoenolates with different electrophiles yie
Cyclopentene and Cyclohexene Annulation via Copper-Catalyzed Conjugate Addition of Acetal-Containing Grignard Reagents
Bal, Swati A.,Marfat, Anthony,Helquist, Paul
, p. 5045 - 5050 (2007/10/02)
The Grignard reagents 2 derived from 2-(bromoethyl)- and 2-(3-chloropropyl)-1,3-dioxolane undergo conjugate addition to a number of α,β-unstaurated ketones in the presence of a catalytic amount of a cuprous salt.The resulting keto acetals, upon treatment with hydrochloric acid, undergo sequential hydrolysis, intramolecular aldol condensation, and dehydration to give cyclopentene and cyclohexene annulation products.The entire series of reactions, starting with the conjugate addition, may be performed as a one flask experiment leading to direct formation of thecyclization products.The Grignard reagents may also be alkylated with epoxides or acylated with an acid chloride to give intermediates that may be converted into cyclic products by pathways related to those above.
