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Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles.

ABSTRACT: Aryl sulfamates, tosylates, and mesylates undergo efficient Ni-catalyzed cross coupling with diverse organostannanes in the presence of relatively unhindered alkylphosphine ligands and KF. The coupling is valuable for difficult bond constructions, such as aryl- heteroaryl, aryl-alkenyl, and aryl-alkynyl, using non-triflate phenol derivatives. A combination of experimental and computational studies implicate an unusual mechanism for transmetalation involving an 8-centered cyclic transition state. This reaction is inhibited by chloride sources due to slow transmetalation of organostannanes at a Ni(II)-chloride intermediate. These studies help to explain why prior efforts to achieve Ni-catalyzed Stille coupling of phenol derivatives were unsuccessful.

SUBMITTER: Russell JEA

PROVIDER: S-EPMC6497415 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles.

Russell John E A JEA Entz Emily D ED Joyce Ian M IM Neufeldt Sharon R SR

ACS catalysis 20190304 4

Aryl sulfamates, tosylates, and mesylates undergo efficient Ni-catalyzed cross coupling with diverse organostannanes in the presence of relatively unhindered alkylphosphine ligands and KF. The coupling is valuable for difficult bond constructions, such as aryl- heteroaryl, aryl-alkenyl, and aryl-alkynyl, using non-triflate phenol derivatives. A combination of experimental and computational studies implicate an unusual mechanism for transmetalation involving an 8-centered cyclic transition state. ...[more]

PMID: 31057986

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