77877-41-9Relevant academic research and scientific papers
Zirconium-promoted epoxide rearrangement-alkynylation sequence
Albert, Brian J.,Koide, Kazunori
, p. 1093 - 1098 (2008/09/18)
(Chemical Equation Presented) Additions of terminal alkynes to electrophiles are important transformations in organic chemistry. Generally, activated terminal alkynes react with epoxides in an SN2 fashion to form homopropargylic alcohols. We have developed a new synthetic method to form propargylic alcohols from epoxides and terminal alkynes via 1,2-shifts. This method involves cationic zirconium acetylides as both the activator of epoxides and nucleophiles. Due to the mild conditions to pre-activate alkynes with silver nitrate, this synthetic method is useful for both electron-rich and electron-deficient alkynes with other acid- and base-sensitive functional groups.
Selenium--Stabilized Anions. Preparation of α,β-Unsaturated Carbonyl Compounds Using Propargyl Selenides. Synthesis of (+/-)-7-Hydroxymyoporone
Reich, Hans J.,Shah, Shrenik K.,Gold Paul M.,Olson Richard E.
, p. 3112 - 3120 (2007/10/02)
The reaction of alkyl halides, carbonyl compounds, and trimethylsilyl chloride with the mono- and dianion (1) prepared by deprotonation of phenyl propargyl selenide with lithium diisopropylamide gives 1- or 3-monosubstituted or 1,3-disubstituted propargyl selenides (3a).Oxidation to selenoxides (3b) results in rearrangement to 2-(phenylseleno)-1,3-disubstituted propenones.The rate of rearrangement of propargyl selenoxides increases dramatically when the phenyl group is replaced by a 2-nitrophenyl group, and an intermediate allenyl selenate ester (7c) can be observed by low-temperature NMR.By appropriate modification of oxidation conditions, modest yields of 2-iodopropenes (e.g., 10) or the selenium-free enones or enals can be obtained.A synthesis of (+/-)-7-hydroxymyoporone (15) and its epimer has been carried out by using the dianion 1 to assemble the carbon skeleton.The preparation of α-lithioallenyl phenyl selenide (26) has been accomplished, and its reaction with electrophiles has been studied.
