N-(3-Benzo[b]thienyl)- and N-(2-benzo[b]thienyl)-imino-triphenylphosphorane—prepared from the corresponding azidobenzo[b]thiophenes—react with α,β-unsaturated aldehydes under mild conditions to give directly benzo-[b]thieno[3,2-b]- and benzo[b]thieno[2,3-b]-pyridines through electrocyclization (and eventual dehydrogenation) of the initial aza Wittig imine products.
N-(3-Benzo[b]thienyl)iminophosphoranes toward the Synthesis of Benzo[b]thieno[3,2-b]pyridines: Reactivity and Alternative Regioselectivity with α,β-unsaturated Ketones and Aldehydes
es 1b–d react with α,β-unsaturated aldehydes and ketones 2a–e to give varying mixtures of the regioisomeric benzothieno[3,2-b]pyridines 3a–d and 4a–d as a result of preferential attack of either imino nitrogen or α-thienyl carbon at the enone carbonyl group. The findings indicate that the progressive replacement of phenyl with methyl P-substituent greatly enhances the reactivity of the phosphorane
新的N-(3-苯并[ b ]噻吩基)亚氨基正膦酸酯1b - d与α,β-不饱和醛和酮2a - e反应,生成区域异构的苯并噻吩并[3,2- b ]吡啶3a - d和亚氨基氮或α-噻吩基羧酸在烯酮的羰基上优先进攻的结果是在图4a - d中。该发现表明,用甲基P-取代基逐步取代苯基大大增强了磷烷1的反应性。 并同时提高了磷烷本身通过α-噻吩基碳添加到烯酮中的倾向。
Tandem Reaction of Azide with Isonitrile and TMSC<sub>n</sub>F<sub>m</sub>(H): Access to N-Functionalized C-Fluoroalkyl Amidine
N-Functionalized C-fluoroalkyl amidines are attracting great attention due to their potential in pharmaceuticals. Herein, we report a Pd-catalyzed tandem reaction of azide with isonitrile and fluoroalkylsilane via a carbodiimide intermediate, providing facile access to N-functionalized C-fluoroalkyl amidines. This protocol offers an approach toward not only N-sulphonyl, N-phosphoryl, N-acyl, and N-aryl
N-官能化的 C-氟烷基脒因其在药物中的潜力而备受关注。在此,我们报道了 Pd 催化的叠氮化物与异腈和氟烷基硅烷通过碳二亚胺中间体的串联反应,提供了对 N-官能化 C-氟烷基脒的简便途径。该协议提供了一种方法,不仅可以用于 N-磺酰基、N-磷酰基、N-酰基和 N-芳基,还可以用于具有广泛底物范围的C-CF 3、C 2 F 5和 CF 2 H 脒。在克规模和生物学评估中进一步转化和 Celebrex 衍生化的完成揭示了该策略的重要效用。
Funicello, Maria; Spagnolo, Piero; Zanirato, Paolo, Journal of the Chemical Society. Perkin transactions I, 1990, # 11, p. 2971 - 2978
作者:Funicello, Maria、Spagnolo, Piero、Zanirato, Paolo
DOI:——
日期:——
Zanirato, Paolo, Journal of the Chemical Society. Perkin transactions I, 1991, p. 2789 - 2796