Total synthesis of brevianamide A

Formation of Nucleophilic Allylboranes from Molecular Hydrogen and Allenes Catalyzed by a Pyridonate Borane that Displays Frustrated Lewis Pair Reactivity

“…[5] Thea llylborane 2 prepared in this way was used in the first total synthesis of Brevianamide A, ah ighly challenging target for organic synthesis,r eported earlier this year.T his demonstrates the ongoing importance of this class of nucleophiles for organic synthesis. [6] We recently reported reversible H 2 activation by the pyridonate borane 3 that can be described as an intramolecular frustrated Lewis pair (FLP). [7][8][9] Ad istinguishing feature of this system is that the H 2 activation is associated with at ransition of the covalently bound pyridonate substituent to adatively bound pyridone ligand (Scheme 2).…”

A unified strategy to reverse-prenylated indole alkaloids: total syntheses of preparaherquamide, premalbrancheamide, and (+)-VM-55599

“…1B ). 2 For example, Williams and co-workers employed a biomimetic intramolecular Diels–Alder reaction to construct the bicyclo ring system en route to (–)-VM5599, rac -pre-paraherquamide, rac -marcfortine C, and (+) and (–)-versicolamide B (forming C 22 –C 6 and C 4 –C 5 , Fig. 1B ) and recently, Lawrence and co-workers leveraged a similar bioinspired approach to access (+)-brevianamide A.…”

“…1B ) and recently, Lawrence and co-workers leveraged a similar bioinspired approach to access (+)-brevianamide A. 2 Notably, a complementary strategy employed by Williams and co-workers featured an intramolecular S N 2′ cyclization in the syntheses of brevianamide B, (–)-paraherquamide A, (+)-paraherquamide B, stephacidins A and B, notoamide B, and avrainvillamide (forming C 22 –C 6 , Fig. 1B ).…”

Die Bildung nukleophiler Allylborane aus molekularem Wasserstoff und Allenen katalysiert durch ein Pyridonatboran, das die Reaktivität eines frustrierten Lewis‐Paares zeigt

“…Das dokumentiert die andauernde Bedeutung dieser Klasse von Nukleophilen fürd ie organische Synthese. [6] Wirb erichteten kürzlich, dass das Pyridonatboran 3,d as als intramolekulares frustriertes Lewis Paar (FLP) betrachtet werden kann, in der Lage ist, H 2 reversibel zu spalten. [7][8][9] Ein charakteristisches Merkmal von 3 ist, dass die Wasserstoff-aktivierung mit einer Umwandlung des kovalent gebundenem Pyridonatsubstituentenz ue inem dativ gebundenen Pyridonliganden einhergeht (Schema 2).…”