Cooperative Tertiary Phosphine/Palladium Catalyzed Nucleophilic Allylation between Morita‐Baylis‐Hillman Carbonates and Alkenes

Abstract

In this work, we report an unusual nucleophilic allylation reaction between isatin‐derived Morita–Baylis–Hillman carbonates and simple alkenes synergistically catalyzed by tertiary phosphines and palladium complexes, through chemoselective assemblies of in situ formed onium salts and η1‐allylpalladium species, respectively. A range of 3,3‐disubstituted oxindoles were easily constructed in moderate to good yields with exclusive linear regioselectivity. Moreover, a number of control and deuterium experiments have been conducted to elucidate the catalytic mechanism.

Cooperative photoactivation/Lewis base catalyzed [4 + 2] annulations of α-diazoketones andortho-amino MBH carbonates to access dihydroquinolinone frameworks

“…To further exploit MBH carbonates, several strategies have been developed in chemical synthesis. A cooperative catalytic system combining Lewis bases and transition metal complexes has brought more vitality to this building block; 13 however, they still participated in the reaction as a 1,3-dipole. Moreover, designing a new type of MBH carbonate is another solution to overcome the limitation of the reaction sites.…”

Substrate-Controlled Diversity-Oriented Synthesis of Novel Polycyclic Frameworks via [4 + 2] and [3 + 2] Annulations of Ninhydrin-Derived MBH Adducts with 3,4-Dihydroisoquinolines

“…Among them, the Morita-Baylis-Hillman (MBH) adducts and their derivatives have been extensively explored due to their multifunctional features, and applied as versatile synthons in diverse annulation reactions, mostly for the construction of polycyclic frameworks via cycloaddition with a large variety dipolarophiles [28][29][30][31][32][33]. In particular, isatins or aldehydes-derived MBH carbonates can act as valuable C1, C2, C3, or C4 synthons, which in situ generated zwitterionic allylic ylide species under Lewis base catalysis [34][35][36][37] or π-allyl metal complexes [38][39][40][41][42][43][44][45], to exhibit universal building blocks for the construction of multifunctional and potentially biologically active ring structures via various [3 + n] [46][47][48][49][50][51][52][53], [2 + n] [54][55][56][57][58], [1 + n] [59][60][61][62][63] annulation reactions. As a result, in the past few years, these annulations of employing the isatin or aldehydes-derived MBH carbonates as substrates have evolved into an extremely vibrant research area and achieved great progress and developments.…”