A procedure has been proposed for the synthesis of tertiary acetylenic alcohols and diols by treatment of phenylacetylene or 2-methyl-3-butyn-2-ol with butyllithium and subsequent reaction of lithium phenylacetylide or lithium 4-lithio-2-methyl-3-butyn-2-olate thus obtained with alicyclic, aromatic, and terpene ketones.
anti-hydromagnesiation of aryl alkynes was established using 1 : 1 molar combination of sodium hydride (NaH) and magnesium iodide (MgI2) without the aid of any transition metal catalysts. The resulting alkenylmagnesium intermediates could be trapped with a series of electrophiles, thus providing facile accesses to stereochemically well-defined functionalized alkenes. Mechanistic studies by experimental
作者:Somsuvra Banerjee、Shivhar B. Ambegave、Ravindra D. Mule、Beeran Senthilkumar、Nitin T. Patil
DOI:10.1021/acs.orglett.0c01596
日期:2020.6.19
By applying the “interplay” mode, which consolidates two key reactivity modes of gold catalysis, namely π-activation mode and cross-coupling mode, the first alkynylative Meyer–Schuster rearrangement is designed and successfully implemented. The current protocol gives straightforward access to enynones, a highly valuable building block, from easily available propargyl alcohol feedstocks. Control experiments
Rhodium-Catalyzed Coordination-Assisted Regioselective and Migratory Three-Point Double Annulation of <i>o</i>-Alkenyl Phenols with Tertiary Propargyl Alcohols
disclose herein a Rh(III)-catalyzed migratory three-point double annulation of o-alkenyl phenols with propargyl alcohols for de novo construction of naphtho furan derivatives in a regio- and chemoselective manner. The protocol orchestrates two new rings with four new bonds in one operation without the need for any additive. Necessary labeled and control experiments are conducted to elucidate the reaction
molecules is always in demand. Oxetanes and azetidines are strained heterocycles that possess unique physicochemical properties and exhibit distinctive chemical reactivity. These together prompted us to design a novel synthetic strategy to access them through photo-catalysed annulative formal 4-endo-dig cyclization of propargylalcohols/amines with benzoquinones. This approach is devoid of any chemical
Access to 4‐Membered Heterocycles via Visible‐Light Triggered Intramolecular Cyclization from Alkynes: Bypassing Unfavorable 4‐endo‐dig Cyclization
作者:Arun Sharma、Ahhyeon Choi、Daniel Yim、Hyungjun Kim、Hyunwoo Kim
DOI:10.1002/adsc.202400337
日期:2024.5.21
oxidant, and coupling‐reagent free strategy to access 4‐membered heterocycle, representing a unique example of visible‐light triggered intramolecular cyclization of propargylic alcohols and amines to access oxetanones and azetidinones respectively. Despite the direct 4‐endo‐dig cyclization from these starting materials has proven to be unfavorable, the formation of key p‐quinone methide intermediacy