Configurational stability of chiral, nonconjugated nitrogen-substituted organolithium compounds generated by tin-lithium exchange of N-[(1-tri-n-butylstannyl)alkyl]imidazolidin-2-ones and -oxazolidin-2-ones

Diastereoselective synthesis of chiral α-aminoorganotributyltins via ring-opening of 2-tributylstannyloxazolidines

“…When two signals have nearly the same chemical shift, whatever the SR or RR configuration of the product, as observed for the methyl in 3b and 3c (entries 6 and 9, Table 2), the assignment was confirmed by conversion of 3b and 3c into the corresponding known tributylstannylated oxazolidinone [15]. [15]. e Signals of 5b-RR overlapped with those of 6b.…”

“…Since previous reports have already shown that chiral aaminoorganotributyltins can be suitable candidates as precursors of a-aminocarbanions, both in achiral or in chiral series [7][8][9][10][11][12][13][14][15][16][17][18], we decided to explore a new route to reach this type of reagents. Our choice was oriented towards the ring-opening of 2-tributylstannyloxazolidines in order to avoid the use of hardly storable a-iodoalkyltins, acyltins or a-stannylalcohols which have been previously used for the stereoselective synthesis of chiral a-aminoorganotributyltins [12][13][14][15][16][17]19,20].…”

“…Our choice was oriented towards the ring-opening of 2-tributylstannyloxazolidines in order to avoid the use of hardly storable a-iodoalkyltins, acyltins or a-stannylalcohols which have been previously used for the stereoselective synthesis of chiral a-aminoorganotributyltins [12][13][14][15][16][17]19,20].…”

Sulfones: new reagents in organocatalysis

“…These compounds are particularly attractive as they are bench stable solids and can be easily obtained by a condensation of a carbamate (46) and a sodium aryl sulfinate with the appropriate aldehyde (47), as shown in Scheme 14. 44 As a-amidosulfones furnish the corresponding imine when treated with a base, 45 they have been widely used in combination with hard organometallic regents or metal stabilized enolates. 46 Based on this thought, in 2005, research groups of Ricci 47 and Palomo 48 In 2006, the research group of Ricci, and soon after of Deng and Schauss, reported the asymmetric addition of malonates (52) or dicarbonylic compounds to a-amido sulfones (48).…”

Indium(III) Chloride‐Catalyzed Conversion of {[(Benzyloxy)carbonyl]amino}‐Substituted Sulfones with 2‐[(Trimethylsilyl)oxy]furan: A Facile Access to γ‐Butenolactone Derivatives Containing a Protected Amino Group

“…The racemic {[(benzyloxy)carbonyl]amino}-substituted sulfones 1 can conveniently be prepared from aldehydes and are generally stable [26]. They were prepared here from aromatic, heteroaromatic, and aliphatic aldehydes.…”