Asymmetric Azidoselenenylation of Alkenes: A Key Step for the Synthesis of Enantiomerically Enriched Nitrogen‐Containing Compounds

Abstract

Chiral, nonracemic azidoselenides such as 2 are useful intermediates for the synthesis of enantiomerically enriched nitrogen‐containing compounds (e.g. 3). The asymmetric electrophilic azidoselenenylation of a variety of alkenes with the sulfur‐containing chiral selenenyl triflate 1 and sodium azide occurred with high facial selectivity to provide an array of azidoselenides, which were further elaborated.

Manganese‐Catalyzed Oxidative Azidation of Cyclobutanols: Regiospecific Synthesis of Alkyl Azides by CC Bond Cleavage

“…[17] These negative results prompted us to reinvestigate various transition-metal catalysts.A fter considerable efforts,wef ound that the use of Mn(OAc) 3 enabled the conversion of cyclobutanol 1a into the desired azide 2a.T he nature of the oxidant was crucial to the reaction outcome (Table 1). Whereas commonly used oxidants,s uch as H 2 O 2 , TBHP,K 2 S 2 O 8 ,and O 2 ,gave poor chemical yields (entries 1-4), hypervalent iodine reagents were promising candidates to promote the redox cycle (entries [5][6][7][8]. Thel ower yields obtained with PIDAa nd PhIO could be attributed to the consumption of TMSN 3 through the generation of highly unstable acyclic azido hypoiodite,which rapidly decomposed at room temperature.…”

“…During the past decade,w idespread interest in the azidation of olefins has provided another solution for the formation of alkyl azides. [8] Alkyl C À Ha nd C À Cb onds are inert but abundant in organic compounds; therefore,the direct elaboration of CÀHand CÀCbonds into target functional groups represents the ideal and most straightforward way for the introduction of functional groups.V ery recently,the groups of Hartwig [9a] and Groves [9b] independently developed elegant C À Hb ond azidation processes by means of iron and manganese catalysis to produce alkyl azides in modest chemical yields (Scheme 1A). [9,10] Although these azidation processes are robust, they primarily occurred at tertiary and benzylic carbon atoms.W eh erein disclose an ovel, manganese-catalyzed azidation of cyclobutanols to efficiently generate alkyl azides by CÀCb ond cleavage.Awide range of g-carbonyl-containing primary, secondary,and tertiary alkyl azides were readily furnished in synthetically useful yields (Scheme 1B).…”

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

“…An interesting class of molecules are the selanyl-1,2,3-triazoles [53–61] which can present some biological applications. As example, 4-phenyl-1-(phenylselanylmethyl)-1,2,3-triazole A (Se-TZ) demonstrated an antidepressant-like effect (Fig.…”

Alkene selenenylation: A comprehensive analysis of relative reactivities, stereochemistry and asymmetric induction, and their comparisons with sulfenylation

“…The mechanism of these addition reactions is further complicated by noticeable influences such as reaction temperature [41,69] and the nature of the counter ion X [33,69]. Furthermore, additional factors stabilizing the seleniranium ion intermediate in step 1, including solvent effects [33,64], strengthening the Se–C bonds [34,55–56], or the presence of heteroatoms or aryl groups in close proximity to Se, were demonstrated to influence the mechanism by resonance stabilization [63] or complexation [31,39]. …”