Heck prolinol vinyl ether

In another example, the aiylation of ketone enolates was achieved indirectly via an intermolecular Heck reaction. In this case, the diastereoselectivity is induced by chelation of a metal-coordinating auxiliary. The inexpensive and commercially available amino alcohol (6()-l-methyl-2-pyrrolidine-methanol was selected as a suitable chiral auxiliary (Scheme 13.47). The prolinol vinyl ether 182 was... 

Larhed and Hallberg developed a highly diastereoselective, chelation-controlled Heck arylation of prolinol vinyl ether by Pd(OAc)2 catalysis in a 1 10 H2O/DMF mixture under air. The arylation provided moderate to good yields (45-78%) and excellent ee values (90-98%) for the isolated cyclopentanones, as shown in Scheme 6.34 [144]. An N-chelated ji-intermediate appears to accounts for the excellent regio- and stereochemical outcome of the arylation. 

Scheme 6.34 Heck arylation of prolinol vinyl ether in water-DMF.

Hallberg and coworkers [19] have reported an asymmetric chelation-controlled Mizoroki-Heck arylation of prolinol-derived vinyl ether 33 (Figure 7.13). In the presence of a catalytic amount of Pd(OAc)2, a regio- and stereo-selective a-arylation of 33 occurs with... 

---

See also in sourсe #XX -- [ ]

---