Arylboration of Enecarbamates for the Synthesis of Borylated Saturated N‐Heterocycles

Abstract

Two catalytic systems have been developed for the arylboration of endocyclic enecarbamates to deliver synthetically versatile borylated saturated Nheterocycles in good regio-and diastereoselectivities. A Cu/Pd dual catalytic reaction enables the synthesis of borylated, α-arylated azetidines, while a Ni-catalysed arylboration reaction efficiently functionalizes 5-, 6-, and 7-membered enecarbamates. In the case of the Cu/Pdsystem, a remarkable additive effect was identified that allowed for broader scope. The products are synthetically useful, as demonstrated by manipulations of the boronic ester to access biologically active compounds.

Peroxidase-induced C–N bond formation via nitroso ene and Diels–Alder reactions

“…R f = 0.68 (1 : 1 n-Hep/EtOAc). 1 H NMR (400 MHz, CDCl 3 ) δ [ ppm] = 7.42-7.30 (m, 5H), 6.64-6.52 (m, 2H), 5.19 (dd, J = 29.2, 12.3 Hz, 2H), 4.85 (td, J = 5.4, 2.8 Hz, 1H), 4.79 (ddd, J = 5.5, 3.8, 1.9 Hz, 1H), 2.29-2.19 (m, 1H), 2.15 (ddt, J = 12.4, 9.0, 3.1 Hz, 1H), 1.52 (tt, J = 12.2, 2.9 Hz, 1H), 1.45-1.36 (m, 1H). 13 25…”

“…The incorporation of nitrogen into organic building blocks through C–N bond forming reactions represents one of the most crucial methodology goals in modern organic chemistry. 1 Especially nitrogen-containing heterocycles, an absolute go-to motif in today's pharmaceuticals, 2 pose a highly important synthetic target. Among the various different ways to conduct carbon–nitrogen bond formations, nitroso reactions occupy something of a niche.…”

Vicinal stereocenters via asymmetric allylic alkylation and Cope rearrangement: a straightforward route to functionally and stereochemically rich heterocycles

“…24 Recent state of the art approaches to complex piperidines include C-H functionalization, [25][26][27][28] from pyridine derivatives by hydrogenation or nucleophilic dearomatization, [29][30][31][32][33][34][35][36] and other methods. [37][38][39][40] A standout route to related cyclohexanes was described by Baran whereby Diels-Alder cycloaddition, desymmetrization, and decarboxylative coupling chemistry are impactfully harnessed. 41…”

Forging C−S Bonds on the Azetidine Ring by Continuous Flow Photochemical Addition of Thiols and Disulfides to Azetines

“…Indeed, 2-azetines have been recently adopted as versatile synthetic platforms to access functionalized azetidines through cycloadditions, [9] batch and flow metal catalyzed hydrogenations, [10,11] acid [10b] and basepromoted [12] additions, and metal-catalyzed transformations. [13,14] However, the use of 2-azetines en route to azetidines through the addition of radicals has been little explored. Zard and coworkers reported the radical addition to N-protected 2azetines using xanthates as radical precursors.…”