Double Reduction of Cyclic Aromatic Sulfonamides: A Novel Method for the Synthesis of 2- and 3-Aryl-Substituted Cyclic Amines
摘要:
The facile double reduction of bicyclic aromatic sulfonamides was used to synthesize a variety of 2- and 3-aryl-substituted pyrrolidines and 2-phenylpiperidine. The method features a combined nitrogen protection and a traceless tether for the transposition of the aromatic moiety from nitrogen to carbon.
An efficient and highly selective domino hydroformylation-reductive sulphonamidation reaction has been developed for the synthesis of sulphonamides using a rhodium/phosphine catalyst.
已开发出一种高效且高选择性的多米诺羟甲基化-还原磺酰胺化反应,用于使用铑/膦催化剂合成磺酰胺。
Direct Synthesis of α-Amino Nitriles from Sulfonamides via Base-Mediated C–H Cyanation
Herein, we disclose a transition-metal-free reaction system that enables α-cyanation of sulfonamides through C–H bond cleavage for the preparation of α-amino nitriles, including difficult-to-access all-alkyl α-tertiary scaffolds. More than 50 substrate examples prove a wide functional group tolerance. Additionally, its synthetic practicality is highlighted by gram-scalability and the late-stage modification
Nickel/Photoredox Dual Catalytic Cross-Coupling of Alkyl and Amidyl Radicals to Construct C(sp<sup>3</sup>)–N Bonds
作者:Shaofang Zhou、Kang Lv、Rui Fu、Changlei Zhu、Xiaoguang Bao
DOI:10.1021/acscatal.1c00731
日期:2021.5.7
The construction of C(sp3)–N bonds via direct radical–radical cross-coupling under benign conditions is a desirable but challenging approach. Herein, the cross-coupling of alkyl and amidyl radicals to build aliphatic C–N bonds in a concise, mild, and oxidant-free manner is implemented by nickel/photoredox dual catalysis. In this protocol, the single electron transfer strategy is successfully employed
在良性条件下通过直接自由基-自由基交叉偶联来构建C(sp 3)-N键是一种理想但具有挑战性的方法。在此,通过镍/光氧化还原双重催化,以简明,温和且无氧化剂的方式将烷基和and基自由基交叉偶联以建立脂族C–N键。在该协议中,成功地采用了单电子转移策略,分别从磺酰基叠氮化物/叠氮基甲酸酯和烷基三氟硼酸酯生成N-和C-中心的自由基。然而,光催化剂诱导的三重态-三重态能量转移机制可能不适用于该反应。激发的光催化剂(Ru II / * Ru II / Ru III / Ru II的氧化猝灭途径))结合可能的Ni I / Ni II / Ni III / Ni I催化循环,基于协同实验和计算研究,提出了镍/光氧化还原双催化C(sp 3)–N键形成的方法。
Transition‐Metal‐Free α Csp
<sup>3</sup>
−H Cyanation of Sulfonamides
site‐selective α‐functionalization of sulfonylamide derivatives through the in‐situ generation of imine intermediates. The N−F sulfonylamides, which could facilitate the elimination to generate imines, are coupled with TBACN to efficiently and mildly afford α‐amino cyanides. Comparing with Strecker reaction, this transformation offers a complementary strategy to efficiently construct α‐amino cyanides
Iron-Catalyzed, Site-Selective Difluoromethylthiolation (−SCF<sub>2</sub>H) and Difluoromethylselenation (−SeCF<sub>2</sub>H) of Unactivated C(sp<sup>3</sup>)–H Bonds in <i>N</i>-Fluoroamides
作者:Hongwei Zhang、Fei Yu、Chuang Li、Peiyuan Tian、Yulu Zhou、Zhong-Yan Cao
DOI:10.1021/acs.orglett.1c01443
日期:2021.6.18
The iron-catalyzed δ-C(sp3)–H bond difluoromethylthiolation and difluoromethylselenation of aliphatic amides with high site selectivity are reported. Essential to the success is the employment of an amide radical formed in situ to activate the inert C(sp3)–H bond and the utilization of the easily handled PhSO2SCF2H and PhSO2SeCF2H as coupling reagents under mild conditions. This scalable protocol exhibits
报道了铁催化的 δ-C(sp 3 )-H 键二氟甲硫基化和脂肪族酰胺的二氟甲基硒化,具有高位点选择性。成功的关键是使用原位形成的酰胺自由基来激活惰性 C(sp 3 )-H 键,并在温和条件下使用易于处理的 PhSO 2 SCF 2 H 和 PhSO 2 SeCF 2 H 作为偶联剂. 这种可扩展的协议展示了具有多功能功能组的广泛基板范围。机理研究表明,反应通过-SCF 2 H 和-SeCF 2 H 自由基转移进行。