A Stereospecific, Intermolecular Biaryl-Coupling Approach to Korupensamine A En Route to the Michellamines

Abstract

By what means and how well can axial chirality be controlled in an intermolecular Suzuki biaryl cross-coupling reaction? The directionality of reductive elimination [Eq. (1)] is completely controlled by using a strategically positioned internal ligand L to afford a single biaryl atropisomer corresponding to the korupensamine A skeleton. TIPS=iPr(3)Si, Ts=H(3)CC(6)H(4)SO(2).

Total Synthesis of the 7,3′‐Linked Naphthylisoquinoline Alkaloid Ancistrocladidine.

“…Lipshutz and Keith synthesised their functionalised heterocyclic portion by allowing the Grignard reagent derived from chloride 1.12 to react with commercially available (S)-TBSglycidol (1.16) to give alcohol 14 Nitrogen functionality was introduced by Mitsunobu inversion with phthalimide, followed by deprotection to give chiral amine which was Chapter 1 Introduction 9 readily converted into dihydroisoquinoline 1.19 using similar chemistry to that described earlier in this section (Scheme 1.4). A useful feature of this sequence is the ability to retain a labile protecting group, such as a TBS (t-butyldimethylsilyl) ether, throughout the synthesis.…”

Copper‐mediated Diastereoselective Conjugate Addition and Allylic Substitution Reactions

“…This group is easily attached to the substrate through esterification of an appropriate alcohol function. The multifunctional character of this group is notable; it can act as an efficient directing [52,53], and a palladium-catalyzed atropselective biaryl coupling [54] have been described. Thus, enoates 127-131 were prepared efficiently by means of a combination of an o-DPPB-directed stereoselective hydroformylation and a Horner-WadsworthEmmons (HWE) olefination (Scheme 6.26).…”

Enantioselective Synthesis of Axially Chiral Biaryls by the Pd-Catalyzed Suzuki−Miyaura Reaction: Substrate Scope and Quantum Mechanical Investigations

“…Uemura,52–54 Nelson,55 Colobert56 and Lipshutz57 demonstrated that axially chiral biaryl products are formed in high yields and excellent selectivities in Pd-catalyzed Suzuki-Miyaura reactions with aryl halides bearing chiral auxiliaries. Later Nicolaou employed chiral phosphines to modulate the selectivity of a diastereoselective Suzuki-Miyaura reaction used in the synthesis of vancomycin 9…”