Fig. 2: Synthesis of sulfilimine 1, reaction optimization and proposed mechanism of the cyclization reaction. | Nature Chemistry

Fig. 2: Synthesis of sulfilimine 1, reaction optimization and proposed mechanism of the cyclization reaction.

From: Bifunctional sulfilimines enable synthesis of multiple N-heterocycles from alkenes

Fig. 2: Synthesis of sulfilimine 1, reaction optimization and proposed mechanism of the cyclization reaction.

a, The sulfilimine 1 was obtained from the reaction of aminoethanol and triflic-anhydride-activated dibenzothiophene-S-oxide in a single step. The reaction optimization shows that both photocatalyst and acid additive are essential for the reactivity; aYield determined from1H NMR with CH2Br2 as an internal standard. bIsolated yield in parenthesis. DCM, dichloromethane; DME, 1,2-dimethoxyethane. b. A radical-polar-crossover annulation process was proposed. The acid additive plays a crucial role in activation of sulfilimine 1 to generate bifunctional NCR B as a key intermediate. DBT, dibenzothiophene. c. X-ray crystal structure of 1 (Supplementary Tables 7 and 8; hydrogen atoms are omitted for clarity). Selected bond distances and angles: S(1)–N(1), 1.591(2) Å; C(1)–S(1)–C(2), 88.85(9)°, C(3)–N(1)–S(1), 116.97(14)°.

Back to article page