Chromium is one of the most earth-abundant transition metals, and ever-increasing attention has been concentrated on the use of Cr as a low-cost alternative to precious metals. Notwithstanding, Cr-catalyzed synthetic chemistry remains largely unexplored, 1 although the industrially important chromium-based Phillips catalyst constitutes approximately 40% of the world's production of high-density polyethylene (HDPE). Transition-metal catalyzed reactions have long been among the most powerful approaches to constructing C-C bonds in modern organic chemistry, paving the way for molecular synthesis of materials, agrochemicals, pharmaceuticals, and industrial chemicals. Historically, such catalytic reactions have been mainly dominated by precious metals including ruthenium, rhodium, 5 iridium, and palladium. Alternatively, first-row transition metals including iron, 8 cobalt, and nickel, have been frequently used as precious metals' counterparts and remarkable advances have been achieved in the past few decades. By contrast to the well-developed C-C bond-forming reactions catalyzed by precious metals and popular first-row metals, limited success has been attained in Cr-catalyzed transformations. Classically, the Nozaki-Hiyama-Kishi (NHK) reaction was realized by using stoichiometric amounts of Cr(II) salts to enable carbonyl additions, which involve a single electron transfer (SET) process to Cr(II) to provide alkyl-Cr(III) nucleophiles. The driving force is to form a strong and thermodynamically favored Cr(III)-O bond. In 1996, Fürstner incorporated a stoichiometric amount of manganese as a reductant and a scavenger to liberate the Cr catalyst from the stable Cr(III)-O bond, thereby disclosing the catalytic NHK reactions (Scheme 1a). Most recently, Glorius 14 and Wang innovatively combined Cr-catalysis with photoredox catalysis to enhance the reaction efficiency and avoid stoichiometric metallic reductants, thus expanding the scope of classical NHK reaction. Since its discovery, the NHK reaction has developed into one of the most efficient approaches to constructing C-C bonds and has been widely used in the total synthesis of natural products. Despite these elegant advances, the scope of the NHK reaction is currently limited to aldehydes and ketones to construct alcohol derivatives. Additionally, most NHK reactions focus on the use of pre-activated electrophilic partners and generally require hygroscopic and easily oxidized CrCl2, which typically necessitates the use of a glove box to prevent the formation of detrimental aqueous CrCl3. Therefore, it's highly desirable to expand the substrate scope of the NHK reaction and explore the catalytic reactivity of more stable Cr(III) salts.