Ochem reagents

addition of hydrogen halides

HX, Markovnikov, neither stereoselective, rearrangement (1 eq forms vinyl halide, 2 eq forms geminal dihalide)

addition of halogens

X2, neither regioselective, anti-addition, no rearrangement (1 eq forms trans-dihalocycloalkene, 2 eq forms tetrahalide)

hydrogenation

H2, Pd/C, neither regioselective, syn-addition, no rearrangement (fully reduces alkyne to alkane)

cis-alkene hydrogenation

H2, Lindlar's catalyst, neither regioselective, syn-addition, no rearrangement (forms cis-alkene)

trans-alkene hydrogenation

Na / NH3 (l), neither regioselective, anti-addition, no rearrangement (forms trans-alkene)

acid-catalyzed hydration

HgSO4, H2SO4, H2O, Markovnikov, neither stereoselective, no rearrangement (forms methyl ketone via tautomerization)

hydroboration-oxidation (alkyne)

1) (Sia)2BH or Cy2BH, 2) NaOH, H2O2, Anti-Markovnikov, syn-addition, no rearrangement (forms aldehyde via tautomerization)

alkyne deprotonation & substitution

1) NaNH2, 2) R-Br, neither regioselective, neither stereoselective, no rearrangement (forms acetylide anion, alkylation chain elongation)

alkyne synthesis from alkene

1) Br2, 2) 3 eq NaNH2, neither regioselective, neither stereoselective, no rearrangement (bromination followed by double elimination to terminal alkyne)

addition of hydrogenhalides (alkene)

HX, Markovnikov, neither stereoselective, carbocation rearrangement

hydration (addition of water)

H+, H2O, Markovnikov, neither stereoselective, carbocation rearrangement

oxymercuration-demercuration

1) Hg(OAc)2, H2O, 2) NaBH4, Markovnikov, neither stereoselective, no rearrangement

hydroboration-oxidation (alkene)

1) BH3•THF, 2) NaOH, H2O2, Anti-Markovnikov, syn-addition, no rearrangement

addition of halogens (alkene)

X2, neither regioselective, anti-addition, no rearrangement

halohydrin formation

X2, ROH, Anti-Markovnikov (OR on more substituted), anti-addition, no rearrangement

hydrogenation (alkene)

H2, Pd/C, neither regioselective, syn-addition, no rearrangement

dihydroxylation

1) OsO4, H2O, 2) NaHSO3, neither regioselective, syn-addition, no rearrangement

ozonolysis

1) O3, 2) (CH3)2S or DMS, neither regioselective, neither stereoselective, no rearrangement (cleaves double bond entirely to ketones and aldehydes)

methyl alkyl halide with strong/strong or strong/weak

SN2, primary substitution pathway, no elimination possible

1° alkyl halide with strong/strong

SN2, standard substitution for unhindered substrates

1° alkyl halide with weak/strong

E2, bulky bases like KOt-Bu or LDA force elimination

1° alkyl halide with strong/weak

SN2, good nucleophiles/weak bases like I- or CN- cleanly substitute

2° alkyl halide with strong/strong

E2, unhindered strong bases like OH- or RO- favor elimination

2° alkyl halide with weak/strong

E2, bulky strong bases cleanly drive elimination

2° alkyl halide with strong/weak

SN2, weak bases that are excellent nucleophiles favor substitution

2° alkyl halide with weak/weak

SN1 and E1, solvolysis leads to carbocation mixture of substitution and elimination

3° alkyl halide with strong/strong or weak/strong

E2, substrate too sterically hindered for substitution

3° alkyl halide with strong/weak

no reaction, substitution blocked and weak base cannot force elimination

3° alkyl halide with weak/weak

SN1 and E1, solvolysis via stable tertiary carbocation intermediate