Chiral secondary alcohols, serving as essential structural motifs, hold significant potential for diverse applications. The exploration of effective synthetic strategies toward these compounds is both attractive and challenging. Herein, we present an asymmetric oxa‐Michael reaction involving aliphatic alcohols as nucleophiles and β‐fluoroalkyl vinylsulfones catalyzed by bifunctional phosphonium salt (BPS), achieving high yields and excellent enantioselectivities (up to 98% yield and 98% ee). Additionally, a sequential process including asymmetric oxa‐Michael and debenzylation, facilitated by BPS/Lewis acid cooperation, was revealed for synthesizing diverse chiral secondary alcohol compounds in high yields (81‐88%) with consistent stereoselectivities. Furthermore, mechanistic explorations and subsequent results unveiled that the enantioselectivity originates from hydrogen‐bonding and ion‐pair interactions between the BPS catalyst and the substrates.

中文翻译：

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双功能鏻盐催化剂有机催化醇与β-氟烷基乙烯基砜的不对称共轭加成

手性仲醇作为重要的结构基序，在多种应用中具有巨大的潜力。探索这些化合物的有效合成策略既有吸引力又具有挑战性。在此，我们提出了一种不对称的 oxa-Michael 反应，涉及由双功能鏻盐 (BPS) 催化的脂肪醇作为亲核试剂和 β-氟烷基乙烯基砜，实现了高产率和优异的对映选择性（高达 98% 的产率和 98% ee）。此外，还揭示了由 BPS/路易斯酸合作促进的包括不对称 oxa-Michael 和脱苄基化在内的连续过程，可以高产率（81-88%）合成具有一致立体选择性的多种手性仲醇化合物。此外，机理探索和随后的结果表明，对映选择性源于 BPS 催化剂和底物之间的氢键和离子对相互作用。