Deprotection of 2-Pyridyl Sulfonyl Group From Pyridine-2-Sulfonamides by Magnesium in Methanol

Pak, Chwang Siek; Lim, Dong Sung

doi:10.1081/scc-100104475

Cited by 41 publications

(26 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Removal of arenesulfonyl groups generally requires drastic reaction conditions. [5] The optically active (S)-2 a and (R)-4 a were desulfonylated on treatment with magnesium in MeOH [34] to give the chiral 1 [b] 1 a 2-…”

Section: Resultsmentioning

confidence: 99%

Enantioselective CC Bond Formation to Sulfonylimines through Use of the 2‐Pyridinesulfonyl Group as a Novel Stereocontroller

Nakamura

Nakashima

Sugimoto

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

Enantioselective CC bond formation to 2‐pyridinesulfonylimines afforded products with good enantioselectivity. Dynamic induction of chirality on the sulfur by coordination of a chiral Lewis acid to the pyridine nitrogen and one of the prochiral sulfonyl oxygens induces enantioselectivity. Since the 2‐pyridinesulfonyl group can easily be removed after the reaction, it acts not only as an activating group but also as an efficient stereocontroller.

show abstract

Section: Resultsmentioning

confidence: 99%

Enantioselective CC Bond Formation to Sulfonylimines through Use of the 2‐Pyridinesulfonyl Group as a Novel Stereocontroller

Nakamura

Nakashima

Sugimoto

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…The deprotected b-aminosulfonamides 60 and 61 could be isolated in 76 and 73 % yield, respectively, after treatment with Mg/MeOH. [51] The lability of the S À C bonds in sulfone 59 was finally utilized for the determination of the absolute configuration of b-sultams 50. With sodium amalgam in MeOH, both the pyridylsulfonyl and phenylsulfonyl groups can be removed in one step to give the 1-phenylpentane amine (62) in a nonoptimized yield of 43 % (Scheme 17).…”

Section: Since Lanthanide Ions Such As Ybmentioning

confidence: 99%

Catalytic Asymmetric Synthesis of β‐Sultams as Precursors for Taurine Derivatives

Zajac

Peters

2009

Chemistry A European J

View full text Add to dashboard Cite

Beta-sultams, biologically interesting sulfonyl analogues of beta-lactams, have been prepared by an organocatalytic asymmetric formal [2+2]-cycloaddition approach of non-nucleophilic imines with alkyl sulfonyl chlorides. In the case of very electron poor N-tosyl imines derived from chloral or ethylglyoxylate, this reaction type was catalyzed by cinchona alkaloids providing the heterocycles in high yield, with good diastereoselectivity and up to 94% ee. Mechanistic investigations suggested that the product formation proceeded via a zwitterionic imine-catalyst adduct. The scope was significantly extended by 2-pyridylsulfonyl imines derived from non-activated aromatic aldehydes employing Yb(OTf)3 as Lewis acid cocatalyst. The synthetic value of the strained enantioenriched beta-sultams was demonstrated by smooth nucleophilic ring opening reactions with O-, N- and C-nucleophiles yielding a variety of acyclic beta-aminosulfonyl (taurine) derivatives (sulfonates, sulfonamides, sulfones) without racemization or epimerization.

show abstract

“…The bidentate N,N chelation of N-(2-pyridylsulfonyl)imines through a favorable five-membered chelate ring [25] with the electrophilic copper salt provides a reasonable explanation for the much higher reactivity of 2-pyridylsulfonylimines over that of nonchelating N-sulfonyl imines. [26] The 2-pyridylsulfonyl group was removed by the simple treatment of the sulfonamide adducts with an excess of Mg in MeOH at room temperature for 2 h. [27] The corresponding primary amines were obtained in 90-94 % yield (Scheme 3).…”

Section: Entrymentioning

confidence: 99%

Alkylation of Aryl N‐(2‐Pyridylsulfonyl)aldimines with Organozinc Halides: Conciliation of Reactivity and Chemoselectivity

2007

View full text Add to dashboard Cite

The best of both worlds: With a coordinating 2‐pyridylsulfonyl group as the N‐activating group, aromatic aldimines show unprecedented high reactivity towards the direct addition of alkyl zinc bromide reagents in the presence of catalytic amounts of Cu(OTf)2. The reaction combines high reactivity with wide functional‐group compatibility to provide ready access to functionalized benzylamines and derivatives (see example). Tf=trifluoromethanesulfonyl.

show abstract

Deprotection of 2-Pyridyl Sulfonyl Group From Pyridine-2-Sulfonamides by Magnesium in Methanol

Cited by 41 publications

References 15 publications

Enantioselective CC Bond Formation to Sulfonylimines through Use of the 2‐Pyridinesulfonyl Group as a Novel Stereocontroller

Enantioselective CC Bond Formation to Sulfonylimines through Use of the 2‐Pyridinesulfonyl Group as a Novel Stereocontroller

Catalytic Asymmetric Synthesis of β‐Sultams as Precursors for Taurine Derivatives

Alkylation of Aryl N‐(2‐Pyridylsulfonyl)aldimines with Organozinc Halides: Conciliation of Reactivity and Chemoselectivity

Contact Info

Product

Resources

About