CHEM 2OA3 Lecture Notes - Trigonal Planar Molecular Geometry, 3Cr Melbourne, Carbocation

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Nu- + r-x r+ (carbocation, achiral, flat, high energy) + nu- r-nu. Stuff written below arrow is almost always a solvent. Since the reactant is trigonal planar (flat), equal chance of attack from above or bottom, so you"ll end up with two enantiomers. What is favored in sn1 reactions: prefers weak nucleophile, need good leaving group (weak base, favors polar solvents. Radical stability (all - are single electrons): tertiary (-cr3) > secondary (-cr2h) > primary (-crh2) > -ch3. Carbocation stability: +cr3 > +cr2h > +crh2 >> +ch3. Weak nucleophile implies sn1 because sn2 pretty much requires strong nucleophile. + + x- h2c=ch2 + h: rate = k[r-x] C(ch3)3br ----(ch3oh) c(ch3)3och3 (minor) (sn1) + alkene (>==