The reaction of the highly functionalized copper reagents RCu(CN)ZnI.BF3 with aldehydes

✍ Scribed by Ming Chang P. Yeh; Paul Knochel; Leroy E. Santa

• Publisher: Elsevier Science
• Year: 1988
• Tongue: French
• Weight: 243 KB
• Volume: 29
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)80372-x

✦ Synopsis

unm~. The new copper reagent RCu(CN)ZnI 2, which may contain important functional groups like the ester, nitie, enoate or imide group, react in the presence of BFs.OEt2 with aldehydes to afford polyfunctional secondary alcohols in good yields (68-93%).

Recently we have reported that organozinc iodide@ 1 can be transmetallated into the corresponding copper derivatives RCu(CN)ZnI 2 by using the soluble salt CuCN.2LiCl. Of special interest is that these copper reagents, unliie the copper compounds prepared from lithium or magnesium organometallics,3*4 may contain important functional groups like the ester, ketone, nitrile, enoate or imide function. They react readily with enones, acyl chlorides and allylic halides and allow the formation of polyfunctional products in high yields.l*2 Some time ago,5 we have reported that alkylzinc halides can also be transmetallated with Cl-Ti(O-i-Prh into the corresponding titanium reagents RTi(O+Pr)3 which react with aldehydes to afford secondary alcohols. However, in this study we have noticed that if functionalized zinc organometallics are used, a large excess of the titanium reagent RTi(OR)3 or RzTi(ORh was required to achieve good conversions.2 1) R'CHO (0.7+u5eq.) CuCN2LiCI 2) BF&Eb (2 eq.), -73% ' H R-zn-I OX, 10 min ) R-Cu(CN)Znl c ,+ -7wCtoao%