Electrophilic Thiocyanation of Tryptamine Derivatives: Divergent Synthesis of SCN-Containing Indole Compounds.

A tandem dearomative electrophilic thiocyanation/cyclization/acylation of indoles was developed for the first time, which is enabled by acyl chloride. A variety of 3-SCN pyrroloindolines were obtained with moderate to excellent yields. Interestingly, following replacement of acyl chloride with methanesulfonic acid, 2-SCN tryptamines were obtained using the same starting substrates and reagents. Furthermore, catalytic enantioselective manner of thiocyanation/cyclization/acylation reaction was also studied. An enantiomer self-disproportionation effect of 3-SCN pyrroloindolines was discovered. A series of chiral 3-SCN pyrroloindolines were obtained with high enantioselectivities.

Phosphoric Acid Catalyzed Electrophilic Thiocyanation of Indoles: Access to SCN-Containing Aryl-Indole Compounds.

A phosphoric acid catalyzed electrophilic thiocyanation of 3-aryl indoles, which provides an efficient and modular approach to SCN-containing 3-aryl indole compounds, was developed for the first time. A variety of 2-SCN-3-aryl indoles were obtained with moderate to excellent yields. Furthermore, catalytic asymmetric manner of this reaction was also studied. Using chiral phosphoric acid as the catalyst, axially chiral SCN-containing 3-aryl indoles were obtained in moderate to good yields with moderate enantioselectivity.

Lewis-Acid-Mediated Thiocyano Semipinacol Rearrangement of Allylic Alcohols for Construction of α-Quaternary Center ß-Thiocyano Carbonyls.

An electrophilic thiocyano semipinacol rearrangement of allylic alcohols has been achieved for the first time by using N-thiocyano-dibenzenesulfonimide (NTSI). This approach provides a direct, simple, and efficient strategy for the formation of thiocyano carbonyl compounds with moderate to excellent yields. Meanwhile, an all-carbon quaternary center was rapidly constructed. In addition, an asymmetric version of this tandem reaction was preliminarily investigated.

TMSCl-Catalyzed Electrophilic Thiocyano Oxyfunctionalization of Alkenes Using N-Thiocyano-dibenzenesulfonimide.

Numerous electrophilic thiocyano oxyfunctionalization reactions of alkenes have been achieved using N-thiocyano-dibenzenesulfonimide, which is a new electrophilic thiocyanation reagent and could be easily prepared in two steps from dibenzenesulfonimide. This approach provides efficient, simple, and modular methods for the formation of SCN-containing heterocycles such as lactones, tetrahydrofurans, dihydrofurans, and dihydrobenzofurans in moderate to excellent yields. Meanwhile, diverse oxa-quaternary centers were rapidly constructed. Additionally, this protocol is free of transition metals and features broad substrate toleraance and mild reaction conditions.

[p53 gene intron 7 polymorphism and its association with oral neoplasms].

OBJECTIVE: To investigate the association between oral neoplasm genetic susceptibility and genetic polymorphism of p53 intron 7. METHODS: The intron 7 ApaI polymorphism of p53 was analyzed in 95 oral neoplasm patients and 105 healthy individuals by utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping assay technique, and direct sequencing was performed in 30 cases which were selected from the patients and controls by random sampling. RESULTS: In oral neoplasms cases, haplotype combinations were T-G 43.2%, C-T 56.8%, and frequencies of genotype were T-G/T-G 15.8%, C-T/T-G 54.7%, C-T/C-T 29.5%, while in controls they were T-G 30.9%, C-T 69.1% and T-G/T-G 10.5%, C-T/T-G 41.0%, C-T/C-T 48.5%. There was a significant difference in the allelic frequency and the genotypical distributions between the oral neoplasm patients and the controls. The individuals with the T-G allele had a slight increasing neoplasm risk than individuals with C-T allele; the OR for T-G versus C-T was 1.69 (95% CI, 1.12 - 2.51). The risk of suffering from oral neoplasms was higher in the individuals of T-G/T-G genotype and of T-G/C-T genotype than in individuals of C-T/CT genotype with odds ratio of 2.48 versus 2.20. CONCLUSIONS: There are two polymorphic points in the 7th intron of human p53 gene, which could be associated with genetic susceptibility of oral neoplasms. T-G allele may be the risk factor of oral neoplasms.