定义Definition
雷福尔马茨基反应是 α-卤代酯与锌粉生成有机锌烯醇盐（雷福尔马茨基试剂），再与醛或酮加成，水解后得到 β-羟基酯的反应。
In the Reformatsky reaction an α-halo ester reacts with zinc to give an organozinc enolate (the Reformatsky reagent), which adds to an aldehyde or ketone; work-up gives a β-hydroxy ester.
机理与特点Mechanism and features
锌插入 C–Br 键形成溴化锌烯醇盐（固态为二聚体）。它的亲核性比锂或镁烯醇盐弱，不会进攻自身的酯基，却能与醛、酮羰基经六元环状过渡态加成，得到锌醇盐，酸化后为 β-羟基酯。
Zinc inserts into the C–Br bond to form a zinc bromide enolate (dimeric in the solid). Being less nucleophilic than lithium or magnesium enolates, it does not attack its own ester but adds to aldehydes and ketones via a six-membered transition state; acidification gives the β-hydroxy ester.
由来Origin
俄国化学家谢尔盖·雷福尔马茨基于 1887 年报道。
Reported by the Russian chemist Sergey Reformatsky in 1887.
应用Applications
β-羟基酯可脱水为 α,β-不饱和酯。与羟醛反应相比，它在中性条件下进行，适合对碱敏感或易烯醇化的酮。现代有不对称、催化及使用其他金属（In、Sm、Cr）的版本。
β-Hydroxy esters dehydrate to α,β-unsaturated esters. Unlike aldol reactions it runs under neutral conditions, suiting base-sensitive or enolisable ketones. Asymmetric, catalytic and other-metal (In, Sm, Cr) variants exist.
反应Reactions
活化锌粉，乙醚、THF 或苯，回流；稀酸后处理
Activated zinc in ether, THF or benzene at reflux; dilute-acid work-up
锌插入 α-卤代酯的 C–X 键。
Zinc inserts into the C–X bond.
锌烯醇盐与羰基经环状过渡态加成。
The zinc enolate adds to the carbonyl through a cyclic transition state.
酸化得 β-羟基酯。
Acidification gives the β-hydroxy ester.
与酮的加成。
Addition to a ketone.
年表Timeline
- 1887
雷福尔马茨基报道该反应
Reformatsky reports the reaction