Enantioselective Allylation of Alkenyl Boronates Promotes a 1,2-Metalate Rearrangement with 1,3-Diastereocontrol
作者:Colton R. Davis、Irungu K. Luvaga、Joseph M. Ready
DOI:10.1021/jacs.1c01242
日期:2021.4.7
Alkenyl boronates add to Ir(π-allyl) intermediates with high enantioselectivity. A 1,2-metalate shift forms a second C–C bond and sets a 1,3-stereochemical relationship. The three-component coupling provides tertiary boronic esters that can undergo multiple additional functionalizations. An extension to trisubstituted olefins sets three contiguous stereocenters.
Generation and Application of (Diborylmethyl)zinc(II) Species: Access to Enantioenriched <i>gem</i>
-Diborylalkanes by an Asymmetric Allylic Substitution
作者:Yeosan Lee、Jinyoung Park、Seung Hwan Cho
DOI:10.1002/anie.201805476
日期:2018.9.24
We report the successful generation of (diborylmethyl)zinc(II) species by transmetallation beteween isolable (diborylmethyl)lithium and zinc(II) halide (X=Br, Cl) and their application in the synthesis of enantioenriched gem‐diborylalkanes bearing a stereogenic center at the β‐position of the diboryl groups by an asymmetric allylic substitution reaction. The reaction has a broad substrate scope, and
nucleophile was developed. The reaction utilizes inexpensive and readily available (CH3CN)3W(CO)3 as a precatalyst and proceeds at 60 °C temperature in the presence of 2,2′-bipyridine and its derivatives as ligand. The synthetic utility of allylic sulfones as electrophile was further demonstrated through Suzuki–Miyaura cross-coupling as showcased by the formal synthesis of (±)-hinokiresinol.
Herein we present a novel strategy based on palladium-catalyzed allylic alkylation by taking advantage of the nucleophilic addition of external fluoride onto gem-difluoroalkenes as the initiation step. The merit of this protocol is highly appealing, as it enables a formal allylation of trifluoroethylarene derivatives through the in situ generation of β-trifluorocarbanions, which otherwise are deemed to
Nickel-catalyzed asymmetric reductive aryl-allylation of unactivated alkenes
作者:Zhiyang Lin、Youxiang Jin、Weitao Hu、Chuan Wang
DOI:10.1039/d1sc01115d
日期:——
Herein we report a nickel-catalyzed asymmetric reductive aryl-allylation of aryl iodide-tethered unactivated alkenes, wherein both acyclic allyl carbonates and cyclic vinyl ethylene carbonates can serve as the coupling partners. Furthermore, the directuse of allylic alcohols as the electrophilic allyl source in this reaction is also viable in the presence of BOC anhydride. Remarkably, this reaction