Synthesis of Spiro-dihydroquinoline and Octahydrophenanthrene Derivatives via Palladium-Catalyzed Intramolecular Oxidative Arylation

Abstract

A method for intramolecular sp C-H oxidative arylation of unactivated cyclic olefins has been developed to access spiro-dihydroquinoline and octahydrophenanthrene derivatives in a straightforward and efficient manner. Bearing picolinamide as a directing group, the alkenyl anilines cyclized to afford spiro-dihydroquinolines in moderate to excellent yields via direct oxidative arylation, while the alkenyl benzylamines furnished the octahydrophenanthrene derivatives in moderate yields via sequential oxidative arylation and double acetoxylation.

Pd-Catalyzed Remote Site-Selective and Stereoselective C(Alkenyl)–H Alkenylation of Unactivated Cycloalkenes

“…1 H NMR (600 MHz, CDCl 3 ): δ 8.55 (d, J = 4.6 Hz, 1H), 8.21 (d, J = 7.8 Hz, 1H), 8.09 (s, 1H), 7.85 (td, J = 7.7, 1.6 Hz, 1H), 7.45–7.39 (m, 1H), 5.66 (s, 1H), 3.97 (d, J = 6.0 Hz, 2H), 2.04–1.99 (m, 4H), 1.67–1.61 (m, 2H), 1.58 (td, J = 5.8, 3.5 Hz, 2H). 1 H NMR of 1p is consistent with the previous report …”

“…Melting points were measured on a Gongyi Yuhua Instrument X-5 digital display micro melting point apparatus and were uncorrected. 1j and 1k were directly obtained from He’s group. , …”

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

“…Furthermore, Shao and He reported the Pd-catalysed cyclisation of alkenyl anilines via oxidative arylation (not shown). 570 …”

An enantiodivergent synthesis of N-Boc-protected (R)- and (S)-4-amino cyclopent-2-en-1-one

“…Therefore, this mixture was directly converted, in moderate yield, into compound 5 by a Mitsunobu reaction involving di-tert-butyl iminodicarbonate. 24,25 Again, the mixture of the minor cisand major trans-1,4-difunctionalised cyclopentenyl compounds proved inseparable. However, on removal of the silyl protecting group (under typical conditions), the more polar alcohol 6 was separable from its minor cis-isomer by flash column chromatography.…”