Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• involvement of a fluorescent intermediate in the cascade synthetic process. Keywords: cascade reactions; copper-catalyzed three-component coupling; gold-mediated 6-endo hydroamination; tandem cyclizations; tetrahydroisoquinoline alkaloids; Introduction The bis-tetrahydroisoquinoline (THIQ) alkaloid family

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

•  9). In addition to perfluoroalkyl iodides, this protocol was further extended to alkyl halides, trifluoromethylthiolate, amines, cycloketone oxime esters, and carboxylic acid N-hydroxyphthalimide esters (NHPI). In 2018, Peters and Fu [57] explored the copper-catalyzed three-component coupling of

Enantioselective additions of copper acetylides to cyclic iminium and oxocarbenium ions

• Jixin Liu,
• Srimoyee Dasgupta and
• Mary P. Watson

Beilstein J. Org. Chem. 2015, 11, 2696–2706, doi:10.3762/bjoc.11.290

• –77%), but poor enantioselectivities (1–11% ee). However, the use of activated acetylenes provides a functional group handle for elaboration, which the authors demonstrate in the preparation of indolizidine 223AB. Building on their initial discovery of a non-asymmetric, copper-catalyzed, three

• -component coupling of pyridine, benzoyl chloride and phenylacetylene [27], the Arndtsen group tackled the challenge of developing a catalyst for the alkynylation of cyclic N-acyliminium ions with unactivated alkynes [28]. Using the reaction of N-acylquinoline and phenylacetylene as their model, they

Copper-catalyzed stereoselective conjugate addition of alkylboranes to alkynoates

• Takamichi Wakamatsu,
• Kazunori Nagao,
• Hirohisa Ohmiya and
• Masaya Sawamura

Beilstein J. Org. Chem. 2015, 11, 2444–2450, doi:10.3762/bjoc.11.265

• not been used for these methods [11]. As related studies we reported earlier the copper-catalyzed conjugate addition of alkylboranes (alkyl-9-BBN) to imidazole-2-yl α,β-unsaturated ketones [12][13][14] and the copper-catalyzed three-component coupling with alkylboranes, alkynoates, and tributyltin

Synthesis of alpha-tetrasubstituted triazoles by copper-catalyzed silyl deprotection/azide cycloaddition

• Zachary L. Palchak,
• Paula T. Nguyen and
• Catharine H. Larsen

Beilstein J. Org. Chem. 2015, 11, 1425–1433, doi:10.3762/bjoc.11.154

• Scheme 1 would streamline the synthesis of alpha-tetrasubstituted triazoles 6. In the first step, our solvent-free copper-catalyzed three-component coupling of cyclohexanone (1), amines 2, and alkynes 3 provides high yields of silyl-protected propargylic amines 4 [24][25]. Trimethylsilyl (TMS) acetylene