Bis-sulfonamide derivatives

A number of other bis(sulfonamides) derived from tran.s-l,2-diaminocyclo-hexane have been developed by several groups and successfully applied to these reactions. Thus, Walsh et al. have reported the use of a series of these ligands in the enantioselective addition of ZnEt2 to benzaldehyde giving excellent enan-tioselectivities, as shown in Scheme 3.39. ... 

Several catalytic systems have been reported for the enantioselective Simmons Smith cyclopropanation reaction and, among these, only a few could be used in catalytic amounts. Chiral bis(sulfonamides) derived from cyclo-hexanediamine have been successfully employed as promoters of the enantioselective Simmons-Smith cyclopropanation of a series of allylic alcohols. Excellent results in terms of both yield and stereoselectivity were obtained even with disubstituted allylic alcohols, as shown in Scheme 6.20. Moreover, this methodology could be applied to the cyclopropanation of stannyl and silyl-substituted allylic alcohols, providing an entry to the enantioselective route to stannyl- and silyl-substituted cyclopropanes of potential synthetic intermediates. On the other hand, it must be noted that the presence of a methyl substituent at the 2-position of the allylic alcohol was not well tolerated and led to slow reactions and poor enantioselectivities (ee<50% ee). ... 

Other Uses. Reagent 1 has been used for enantioselec-tive enolborination, albeit with poor (1.1 1) selectivity. Similar bis-sulfonamide-derived boron Lewis acids have been used for aldol additions, "" ester-Mannich reactions, Diels-Alder reactions, Ireland-Claisen reactions, and [2,3]-Wittig rearrangements. Similar bis-sulfonamide-derived aluminum Lewis acids have been used for aldol additions, Ehels-Alder... 

Cyclic derivatives 75 lead to higher levels of enantioselectivity but their preparation require more effort than for the simpler reagents 74 [104,105]. Corey and co-workers reported the bis (sulfonamide) derivatives of type 76, which provide very high enantioselectivity (>95% ee) in the case of unsubstituted allyl and 2-substituted reagents [30]. The recent advent of the Lewis acid-catalyzed manifold (Section 6.3.1.2) opened new doors for enantioselective aUylborations and motivated the reexamination of several chiral auxiliary systems. In this perspective, reagents 73, one of the two classes... 

Chiral boron(III) complexes can catalyze the cycloaddition reaction of glyoxy-lates with Danishefsky s diene (Scheme 4.18) [27]. Two classes of chiral boron catalyst were tested, the / -amino alcohol-derived complex 18 and bis-sulfonamide complexes. The former catalyst gave the best results for the reaction of methyl glyoxylate 4b with diene 2a the cycloaddition product 6b was isolated in 69% yield and 94% ee, while the chiral bis-sulfonamide boron complex resulted in only... 

The following C2-symmetric bis-sulfonamide is a more efficient controller of stereoselectivity in aldol additions. The incorporation of this ligand into the bromodiazaborolane, subsequent generation of the boron enolate derived from 3-pentanone, and addition to achiral aldehydes preferentially leads to the formation of ijn-adducts (synjanti 94 6 to >98 2) with 95-98% ee. Chemical yields of 85-95% are achieved51. 

Scheme 3.39 7>aw5-l,2-diaminocyclohexane-derived bis(sulfonamides) ligands for addition of ZnEt2 to benzaldehyde. 

Scheme 3.40 3>aw -l,2-diaminocycloliexane-derived bis(sulfonamides) ligands for additions of ZnEt2 to aldehydes. 

Scheme 6.23 Simmons-Smith cyclopropanations of allylic alcohols with )-phenylalanine-derived bis(sulfonamides) ligand.

In early studies of these reactions, the turnover efficiency was not always high, and stoichiometric amounts of the promoters were often necessary to obtain reasonable chemical yields (Scheme 105) (256). This problem was first solved by using chiral alkoxy Ti(IV) complexes and molecular sieves 4A for reaction between the structurally elaborated a,/3-unsaturated acid derivatives and 1,3-dienes (257). Use of alkylated benzenes as solvents might be helpiul. The A1 complex formed from tri-methylaluminum and a C2 chiral 1,2-bis-sulfonamide has proven to be an extremely efficient catalyst for this type of reaction (258). This cycloaddition is useful for preparing optically active prostaglandin intermediates. Cationic bis(oxazoline)-Fe(III) catalysts that form octahedral chelate complexes with dienophiles promote enantioselective reaction with cyclopentadiene (259). The Mg complexes are equally effective. 

The use of bis(sulfonamide) ligands derived from stilbenediamine in the asymmetric addition of diethylzinc to benzaldehyde has resulted in large changes in product ee over the course of the reaction.106 This effect has been attributed to autoinduction. During the reaction the catalyst evolves by incorporation of the product of the asymmetric addition reaction. 

The synthesis of darunavir (1) is shown in Scheme 12. Optically active bis-THF alcohol (-)-ll was converted to activated mixed carbonate 46 by treatment with N,N-disuccinimidyl carbonate (DSC) in the presence of triethylamine.30 For the synthesis of the hydroxyethylsulfonamide isostere, epoxide 38 was treated with isobutyl amine (47) in 2-propanol at reflux to provide the corresponding amino alcohol. Reaction of the resulting amino alcohol with p-nitrophenylsulfonyl chloride in the presence of aqueous NaHC03 afforded the sulfonamide derivative 48 in 95% yield for the two steps. This was converted to darunavir in a three-step process, involving (1) catalytic hydrogenation of nitro to an amine, (2) removal of the Boc group by exposure to trifluoroacetic acid in... 

A catalytic approach to the synthesis of arylglycines was proposed by Evans and coworkers using enantioselective amination of iV-acy 1 oxazolidinones [54], Metallo-bis(sulfonamide) complexes derived from chiral diamines are potential chiral catalysts. The magnesium-bis(sulfonamide) complex 109 was generated by treating (S,S)-bis(sulfonamide) 108 with dimethylmagnesium in dichloromethane (Scheme 50). 

The titanium Lewis acid derived from diol (463) could be employed in catalytic amounts (0.1 mol equiv.) when molecular sieves were present (entries 2, 3). Under these conditions, cycloaddition of the crotonoyl dienophile was significantly more enantioselective compared with that of the acryloyl analog. On the other hand, both adducts (467a) as well as (467b) were obtained in 2% ee using the I wis acid (465) (0.1-0.2 mol equiv.), prepared in situ from bis-sulfonamide (464) and AlMes (entries 4, 5). 

The number of chiral diazaaluminolidine catalysts has been extended by Dymock, Kocienski and Pons, who introduced the more convenient to handle trimethylsilyl-ketene [31]. The catalysts in this study were prepared from slightly different sulfonamides but asymmetric induction was comparable with that obtained with the ketene and similar aldehydes. With trimethylsilylketene, two diastereomers are possible and in all examples studied the cis isomer 126 was the predominate product. TTie reactions in Table 7 were performed with 30 mol % catalyst—with 20 mol % catalyst the reaction is incomplete. A more active catalyst can be prepared from the bis-trifluoro-methylsulfonyl derivative of 128, but asymmetric induction was low. It was reported that ortho substituents on the aryl sulfonamide were necessary for higher induction but data were provided only for the aryl sulfonamide substituents summarized in Table 7. Both symmetrical and unsymmetrical diazaaluminolidines were examined as catalysts in an attempt to optimize asymmetric induction but significant differences were not found. The catalyst prepared from the symmetric bis-sulfonamide 128 with Ar = 2,4,6-tri-/yo-propylphenyl did not give any reaction even at 100 mol %. 

An effective chiral aluminum catalyst prepared from the bis-sulfonamide 263 was reported by Corey, Imwinkelried, Ikul, and Xiang for the Diels-Alder reaction of N-acyloxazolidinones [55]. They found that 10 mol % catalyst 266 would effect the reaction of A-acrylyl derivative 261 in 10 min at -78 °C to give the endo adduct 262 in 92 % yield and 91 % ee. The reaction of the N-crotyl derivative 197 was slower but... 

Transformation of 1,3-diamino-2-propanol (144) into vicinal diamines has been reported. Thus, the bis(benzyloxycarbonyl) derivative of (144) was mesylated to give (145), which was converted into 1-benzyloxycarbonylaziridine (146). Acetic acid and HCl reacted at the ring carbon of (146) affording 2,3-diamino-1-propanol (147) and l-chloro-2,3-diaminopropane (148 Scheme 68). On the other hand, the reaction of (146) with Grignard reagents and sodio malonates resulted in the loss of the carbamate protecting group. In contrast, the sulfonamide derivative (149) could be converted into diamines (151) and (152) via 1-tosylaziridine (150 Scheme 68). 

The cycloaddition of functionalized cyclopentadiene and dienophile 83 was better performed by use of an entirely different, non-phenoxide-type aluminum complex (Scheme 6.53). Thus a chiral catalyst endowed with the more electron-with-drawing bis (sulfonamide) ligand was explored by Corey and coworkers [73]. The reaction of the trons-crotyl derivative 83 and cyclopentadiene with 20 mol% 84 as catalyst at -78 °C for 16 h provided adduct 85 in 88% yield and 94% ee. The ad-... 

A decade later, Corey introduced an effective aluminum-diamine controller for Diels-Alder and aldol additions. The C2-symmetric stilbenediamine (stien) ligands are available in good yield from substituted benzils, which are in turn derived from benzoic acids, aryl aldehydes, or aryl bromides [48]. Formation of the active catalyst 3 is achieved by treatment of the bis(sulfonamide) with tri-methylaluminum recovery of the ligand was essentially quantitative. Acryloyl and crotonyl imides 4 are particularly effective dienophiles for this system, as shown in Scheme 4. 

King and Krespan (1974) used the bis-trifluoroacetamide derivative of a diamine rather than the bis-sulfonamide to prepare a diaza-crown. The tri-... 

Polyamine chain extension, 48-56 by acrylamide 51, 52. 53 by aziridine 48,49 by l-bromo-3-chloropropane, 55 by (2-bromoethyl)phthalimide, 51 by 3-bromopropylphthalimide, 53 by chloroacetonitrilc, 51 by chloroacetyl chloride. 50 by lV-(2-chloroethyl)acetamide, 52 by derivatives of chloroacetic acid. 50 by dichloro(o)-bromoalkyl)boranes. 56 by IV-ethylchloroacetamide, 52 by 3-phthalimidopropyl tosylate, 54 by /V-tosyl-2-bromoethylamine, 49 by 2-(N-tosylamino)ethyl tosylate. 49 by Af-tosylaminoacetyl chloride, 50 Polyamino diols. 59 Polyaza-crown macrocycles. 349-367 alkyl-substituted. 364.365 from bis-sulfonamides, 358-361 from diacid dichlorides, 352-357 from diesters, 352-357 from dihalides, 362-366 from diols, 366 from ditosylates. 362-366 Polyaza-crown macrocycles (miscellaneous), table. 392... 

The 3-alkyl-3,4-dihydro-2//-l-thia-2,4-diazine 1,1-dioxide 224 is produced by heating the appropriate aldehyde with 2-aminobenzenesulfonamide in iV-methyl-2-pyrrolidone (NMP) at 100°C <2001BML3103>. 3-Aryl-3,4-dihy-dro-2//-l-thia-2,4-diazine 1,1-dioxides 225 are the products of heating preformed bis(sulfonamides) with aryl aldehydes in dimethyl sulfoxide (DMSO) <20040JC373>. The 3,4-annulated derivative 226 is the result of a reaction between the corresponding 2-aminobenzenesulfonamide and homophthalaldehyde <1996AP51>. 

Enantioselective aromatic Claisen rearrangement was reported from our group in 1997 [65]. The Claisen rearrangement of catechol mono allyl ether derivative 80 was catalyzed by chiral bis-sulfonamide-boron reagent 81. Although a stoichiometric amount of chiral reagent is required for this reaction, this is only one successful example of the enantioselective aromatic Claisen rearrangement. 

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