Transmissive Olefination Route to Putative “Morinol I” Lignans

Abstract

A series of morinol-type lignans were rapidly assembled using a Grignard-based transmissive olefination. In combination with palladium-catalyzed arylations, the strategy provides stereoselective access to (7Z, 7′E), (7E, 7′E), (7E, 7′Z) morinol diastereomers and the (7Z, 8′E) and (7E, 8′E) conjugated analogs. Critical for the E/Z-stereoselectivity is a new, general method for converting alkenenitriles to alkenemethanols that circumvents the enal E/Z isomerization commonly encountered during conventional i-Bu2AlH reduction.

Synthetic Applications of the Parkins Nitrile Hydration Catalyst [PtH{(PMe2O)2H}(PMe2OH)]: A Review

“…As in the previous case, formation of 49 was accomplished through a hydration/Hofmann rearrangement sequence from the corresponding nitrile, the hydration step being again promoted by the Parkins platinum catalyst 1. Finally, Fleming and co-workers reported the preparation of a series of morinol-type lignans 55 starting from α,β-unsaturated nitriles 53 (Scheme 13) [62]. The selective transformation of the alkenenitrile unit of 53 into the allylic alcohol one involved an initial hydration step, catalyzed by complex [PtH{(PMe2O)2H}(PMe2OH)] (1), followed by an acylation/reduction of the resulting amides 54.…”

Preparation of Imides via the Palladium-Catalyzed Coupling Reaction of Organoborons with Methyl N-[Methoxy(methylthio)methylene]carbamate as a One-Carbon Elongation Reaction

“…Usually, imides are prepared by condensation reactions of amides with acylating reagents ( A ) or by reaction of activated carboxylic acid derivatives with amides ( B ) . Therefore, these methods require the corresponding carboxylic acids or their derivatives as starting materials, thereby limiting the variation of their syntheses.…”