Efficient asymmetric synthesis of 3-substituted β-sultams

Asymmetric Synthesis ofcis-3,4-Disubstituted β-Sultams

“…According to GP 3 the compound (S,R)-4b (47 mg, 0.14 mmol) was cyclised to the b-sultam (S,R)-5b. After column chromatography the product was obtained as a yellow oil (29 mg, 82%); R f 0.22 (Et 2 O-n-pentane, 1:2); de, ee ≥96%; CHCl 3 7, 91 (26), 84 (11), 78 5, 77 5 7, 144 (28), 143 (19), 129 (29), 128 (18), 118 (19), 117 (46), 115 (12), 108 (8), 107 7, 106 (77), 105 (6), 104 (6), 92 (9), 91 (100), 77 5, 70 (33), 65 (16), 57 (50), 56 7, 55 5 (m, 1 H, CHCHHCH 2 ), 1.98 (dddd, J = 4.5, 8.0, 8.9, 13.9 Hz, 1 H, CHHCH 2 Ph), 2.44 (dddd, J = 5.2, 8.7, 11.6, 13.6 Hz, 1 H, CHHCH 2 Ph), 2.68 (ddd, J = 8.2,8.2,13.9 Hz,1 H,CHHPh), 2.92 (ddd, J = 4.9,8.9,13.8 Hz,1 H,CHHPh), 3.59 (ddd, J = 4.2, 8.5, 9.9 Hz, 1 H, NCH), 4.45 (dddd, J = 1.7,4.4,8.4,11.4 Hz,1 H,SCH), 5.51 (s,1 H,NH),5 H,PhH). 13 C NMR (100 MHz, CDCl 3 ): d = 13.9 (CH 3 ), 22.3 (CH 2 CH 3 ), 27.0 (CH 2 Bn), 28.2 (CH 2 CH 2 CH 3 ), 30.4 (CH 2 CH 2 CH 2 CH 3 ), 33.7 (CH 2 Ph), 45.4 (NCH), 74.4 (SCH), 126.6 (pCPh), 128.6, 128.7 (oCPh, mCPh), 139.9 ( ipso CPh).…”

“…MS (EI, 70 eV): m/z (%) = 202 (45), 186 (15), 176 7, 169 (11), 160 (5), 159 (6), 150 (6), 147 (11), 146 (80), 145 (28), 144 (64), 143 (10), 133 5, 131 5, 130 (10), 129 (60), 128 (11), 121 5, 120 (12), 118 (19).…”

“…18 With this precursor in hand, we were able to synthesise a variety of 3-substituted b-sultams. 19 Only one further enantioselective synthesis is described in the literature. 20 Baldoli et al used chiral tricarbonyl(h 6arene)chromium(0) complexes in the synthesis of 3-substituted 1,2-thiazetidine 1,1-dioxide derivatives.…”

[2 + 2] Annulation of Aldimines with Sulfonic Acids: A Novel One‐Pot cis‐Selective Route to β‐Sultams

“…The [2 + 2] cycloaddition reported for β‐sultam synthesis utilizes mainly sulfene intermediates with imines,10 mesyl chloride with chiral imines,11 or alkenes with N ‐sulfonylamines 12. The intramolecular cyclization strategy involves use of amino acids followed by introduction of the sulfur moiety,13 β‐amino sulfonic acids,6 heterocyclic sulfonates14 or β‐aminosulfonyl chlorides,15 for diastereo‐ and enantioselective synthesis of β‐sultams 6,8,16…”

Synthesis of novel 2,3‐dihydro‐3‐hydroperoxy‐2‐aryl‐4,5‐diphenylisothiazole 1,1‐dioxides and their epoxidation ability

“…They show biological activities such as antibacterial [5,6], anticonvulsant [7,8], sedative-hypnotic [9], and peptidomimetic [10,11]. Sultams have found application as chiral auxiliaries in several asymmetric processes such as Diels-Alder reactions [12,13], alkylation [14], and dihydroxylation [15] and are used in enantioselective catalysis [16].…”