CHEM 6410 RXNs

great LGs

weak bases

OTs, OMs, I-, BR-, Cl-, (COO- and NH3 are ok LGs)

sulfonates are better than halides

what makes a good nucleophile

strong base

left on PT, up on PT (in polar aprotic solvent), and down on PT (in polar protic solvents)

not bulky base

high electron density but not steric hindrance

Gabriel Synthesis: SM

alkyl halide

Gabriel Synthesis: key reagents

pthalamide and base

Gabriel Synthesis: purpose

to create a primary amine

Williamson Ether: SM

alkyl halide and alkoxide

Williamson Ether: key reagents

alkyl halide and base

Williamson Ether: purpose

create ethers (or C-O bonds) using alkoxide (deprotonate OH) or tosylates

Finkelstein: purpose

synthesize alkyl iodides from alkyl chlorides or bromides through a halogen exchange reaction driven by the insolubility of the resulting metal halide (like NaCl or NaBr) in acetone

Finkelstein: SM

alkyl halids like R-Cl and R-Br

Finkelstein: key reagent

NaI in acetone, or R-Cl, R-Br, OMs, OTs, MsCl

Heine: purpose

ring expansion via double inversion

N-acylaziridines into 2-oxazolines

Heine: key reagents

NaI or KSCN

TMS-I

Heine: SM

N-acylaxiridine

Appel: purpose

converts alcohols into alkyl halides with an inversion of bond

Appel: key reagents

PPh3 and CCl4/ CBr4

Appel: SM

alcohols

Mitsunobu: purpose

converts primary or secondary alcohols into antoher functional groups (such as esters, ethers, and amines)

Mitsunobu: key reagents

PPh3 and DEAD/DIAD and H-Nuc

Mitsunobu: SM

alcohol

SN2 electrophiles

primary then secondary are best

common polar protic solvents

H2O, MeOH, EtOH,

common polar aprotic solvents

acetone, DMSO, and DMF; ethers like diethyl ether and THF; halogenated solvents such as dichloromethane and chloroform; and hydrocarbons including hexane, toluene, and benzene

example of strong base

NaH, LDA, LHMDS

example of strong acid

HCl, HBr, HI, HNO₃, H₂SO₄, HClO₃, HClO₄