A novel preparation of allylic tins applying the reduction of tin(IV) chloride with iodide and its application

卤化锡（IV）与二氯甲烷中的碘化物通过生成五卤丁酸盐（IV）还原为三卤丁酸盐（II）。三卤丁酸盐（II）与烯丙基氯化物或烯丙基甲磺酸盐反应生成烯丙基三卤丁，并与醛类发生亲核加成，生成相应的同丙烯醇。将三卤丁酸酯（II）应用于丙基三卤丁和烯基三卤丁的制备。(1)羰基烯丙基化：由3-氯丙烯或2-甲磺酸丙烯与氯化锡（IV）和三等量的四丁基碘化铵（TBAI）合成2-丙烯基三氯锡，使醛发生亲核加成反应，得到相应的高收率均烯丙基醇。羰基烯丙化与1-氯-2-丁烯的反应收率仍然很低。用碘化锡代替氯化锡，减少了TBAI（2等摩尔量）的用量，提高了1-氯-2-丁烯羰基烯丙化反应的产率。1,3-咪唑烷-2-酮用碘化钠代替TBAI。(2)羰基烯丙基化和丙炔基化：与上述羰基烯丙基化类似，羰基烯丙基化和丙炔基化是用2-丙基氯或甲磺酸进行的。甲磺酸1-甲基-2-丙基或甲磺酸2-丁基与醛反应分别生成相应的2-甲基-3-丁-1-醇或2-甲基-2,3-丁二烯-1-醇。

Tin(IV) halides were reduced to trihalostannates(II) with iodide in dichloromethane via the formation of pentahalostannates(IV). The trihalostannates(II) reacted with allylic chlorides or allylic mesylates to prepare allyltrihalotins, which caused nucleophilic addition to aldehydes to afford the corresponding homoallylic alcohols. The trihalostannates(II) were applied into the preparation of propargyltrihalotins and allenyltrihalotins. (1)Carbonyl allylation: 2-Propenyltrichlorotin, derived from 3-chioropropene or 2-propenyl mesylate with tin(IV) chloride and three equimolar amount of tetrabutylammonium iodide (TBAI), caused nucleophilic addition to aldehydes to afford the corresponding homoallylic alcohols in high yields. The carbonyl allylation with 1-chloro-2-butene remained in low yields. The use of tin(IV) iodide instead of tin(IV) chloride cut down the amount of TBAI (two equimolar amount) and enhanced the yields of carbonyl allylation with 1-chloro-2-butene. Sodium iodide instead of TBAI was utilized in 1,3-imidazolidin-2-one. (2)Carbonyl allenylation and propargylation: Carbonyl allenylation and propargylation were carried out with 2-propynyl chloride or mesylate similarly to the carbonyl allylation mentioned above. The reaction of 1-methyl-2-propynyl mesylate or 2-butynyl mesylate with aldehydes afforded the corresponding 2-methyl-3-butyn-1 -ols or 2-methyl-2,3-butadien-1-ols respectively.