Transition metal-catalyzed cross-coupling reactions (CCRs) are recognized as powerful methods for the synthesis of pharmaceuticals, polymers, and commercial products. Despite pioneering works by Kochi in the 1970's revealing the potential of simple iron salts as catalysts for carboncarbon CCRs, 2 this field has been dominated by palladium and nickel catalysis. Considering the inherent attractive features of iron (e.g., low toxicity, earth abundance, environmentally benign, and low cost), in the last two decades, there has been a surge in the development and, equally important, mechanistic understanding of ironcatalyzed cross-couplings. However, in contrast to other transition metal-catalyzed CCRs, general and practical examples of asymmetric Fe-catalyzed cross-couplings involving sp -hybridized coupling partners are extremely rare. To highlight the state-of-the-art, seminal reports by the Nakamura and Byers groups disclosed two-component asymmetric Fe-catalyzed cross-couplings between alkyl halides and organometallic nucleophiles (Figure ). However, these methods are severely limited to the use of activated radical precursors (i.e., α-halo esters and benzyl alkyl chlorides) and formation of one carbon-carbon bond (i.e., two-component cross-couplings). In part, the lack of general asymmetric Fe-catalyzed CCR methods can be attributed to the high reactivity and instability of alkyl radicals that are prone to undergo a plethora of side reaction (e.g., SET, β-hydride elimination, dimerization, H-atom abstractions, etc.) prior to undergoing enantioselective C-C bond formation with a chiral organoiron species. Another major and long-standing challenge in this area is the lack of detailed understanding of the factors (i.e., speciation, spin state, oxidation state, and coordination, etc.) controlling selectivity and reactivity of iron species under catalytic conditions. We have initiated a program aimed at using experimental and computational tools to elucidate the mechanisms of ironcatalyzed cross-coupling reactions and, in turn, use this information to develop Fe-catalyzed multicomponent CCRs. 11 Inspired by these results and elegant work by the Morken and Nevado 13 groups on nickel-catalyzed asymmetric CCRs (Figure ), we hypothesized that vinyl boronates could serve as effective lynchpins to promote radical capture, relay, and enantioselective cross-coupling of α-boryl radicals with well-defined chiral bisphosphine-iron species (Figure ). If successful, this work can not only completement existing nickel-based catalytic systems for the synthesis of diverse and chiral alkyl boron reagents (Figure ) but also open the doors for the development of multicomponent iron-catalyzed asymmetric cross-couplings. Herein we report the first general and broadly applicable use of commercially available iron salts and chiral bisphosphine ligands to promote asymmetric multicomponent radical cross-coupling between a range of (difluoro)alkyl halides, Grignard reagents, and vinyl boronates. Based on prior work by us 11f and others, we initiated our studies using tert-butyl bromide, vinylB(pin), and 4fluorophenylmagnesium bromide as model substrates to investigate the asymmetric three-component iron-catalyzed CCR. We hypothesized that under slow addition of Grignard reagent, we could generate the active chiral monoaryl-and Table . Optimization of Asymmetric Dicarbofunctionalization of Vinyl Boronates using Iron Catalysis. a a Reaction conditions: All reactions were performed using t-butyl bromide 1 (0.2 mmol, 2 equiv.), vinylboronic acid pinacol ester 2 (0.1 mmol, 1 equiv.), 4-fluorophenyl Grignard 3 (0.2mmol, 2 equiv.), and 1 mL of 1.0 M solution of THF. Aryl Grignard was added dropwise over an hour via syringe pump. Crude product was directly oxidized with 3.0 equiv. NaBO3•4H2O in 1:1 H2O:THF and purified. Er was determined by HPLC using a chiral stationary phase on Daicel's CHIRALPAK® AD-H column.