5b

Question 1

whats an imine

Answer 1

R R = NR

Question 2

whats the pH of an imine

Answer 2

4-6

Question 3

how do we form an imine

Answer 3

ketone + primary amine

acid catalyst: H+

Question 4

describe imine formation from a ketone and a primary amine

Answer 4

O on C=O attacks H+
loe pair on amine attacks C
1-2 addition
base deprotonates the amine
OH is protonated
lone pair on amine helps remove water LG.
giving us an imine

Question 5

what is an imminium ion

Answer 5

R R = N R R +

Question 6

whats an organometallic

Answer 6

C - METAL

Question 7

in organometallics,, what are the charges

Answer 7

C is slightly -
Metal is slightly +

Question 8

organolithium

Answer 8

C-Li

Question 9

organomagnesium

Answer 9

C-Mg X

Question 10

in organo magnesium,, what can X be

Answer 10

Cl
Br
I

Question 11

what do organometallics do

Answer 11

undergo nucleophilic addition reactions with ketones + aldehydes to give alcohols

Question 12

what are organometallic reactions usually carried out in

Answer 12

THF
Et2O

aprotic solvents

Question 13

bromobutane + Li in Et2O

Answer 13

alkyl lithium

the charges on the C and substituent switch!!

from C being +
to C being -

gives LiBr as a product aswell

Question 14

bromobutane + Mg in Et2O

Answer 14

alkyl magnesium bromide

Grignard reagent

charges switch from C+ to C-

Question 15

adding alkyl lithium to ketone // aldehyde

Answer 15

R-Li bond donates e- and attacks the C=O
= e- move to the O giving O-

O- then attacks H3O+ to give an alcohol.

either secondary or tertiary

Question 16

reaction that forms alcohols from ketones or adehydes

Answer 16

1,2 addition

irreversible

Question 17

making primary alcohols with MgXOH

Answer 17

H C=O H formaldehyde

the bond between MgX - R attack the C

then reacting with H3O gives an alcohol,, primary

Question 18

what do we react carbonyls with to get alcohols

Answer 18

alkyl lithium

MgX - R

Question 19

whats special condition needs to be present when making alcohols using R - MgX

Answer 19

in needs to be in anhydrous conditions as its sensitive to water

Question 20

how do we synthesise a carboxylic acid

Answer 20

react R - MgX or R -Li with CO2

CO2 addition reactions

Co2 must be solid and in THF or Et2O

Question 21

reaction for making carboxylic acids from CO2 and R-MgX

Answer 21

R-MgX bond attacks the C in CO2

attacks H3O+ to protonate the O- and give an alochol // carboxylic acid group

Question 22

bromo butane to carboxylic acid!!

Answer 22

bromobutane + Mg in Et2O

gives butane - MgBr

add solid CO2 electrophile

gives butane CO2MgBr

add H3O+

gives butane - CO2H

Question 23

addition of a metal hydrides to ketones or aldehydes

Answer 23

gives alcohols

Question 24

metal hydrides

Answer 24

NaBH4
LiAlH4

Question 25

what type of H do metal hydrides have

Answer 25

nucleophilic the B-H or the Al-H bond attack smt positively charged

Question 26

ketone + metal hydride

Answer 26

secondary alcohol

Question 27

aldehyde + metal hydride

Answer 27

primary alcohol

Question 28

bromonium ion

Answer 28

BH4 - - charge as B is in group 3

Question 29

BH3

Answer 29

6e- in the B-H sigma bonds 1 empty p orbital

Question 30

organolithium derivative

Answer 30

R - Li

Question 31

organolithium derivative charge

Answer 31

C = p- Li = p+

Question 32

steps to think of mechanism for organometallics

Answer 32

1. is the product a 1, 2, 3 alcohol 2. reactant probably had one less carbon 3. e- need to come from a C-Metal bond so add the Metal

Question 33

if product is a 1 alcohol the reactant must be

Answer 33

H H =O formaldehyde

Question 34

if the product is a 2 alcohol the reactant must be

Answer 34

aldehyde

Question 35

if the product is a tertiary alcohol the reactant must be

Answer 35

a ketone

Question 36

what are organometallics used for

Answer 36

they react with aldehydes and ketones,, aka carbonyls,, under 1,2 irreversible reactions to form alcohols.

Question 37

what must be used when an organometallic reacts with a carbonyl under 1,2 addition irreversible reactions

Answer 37

THF Et2O aprotic solvents

Question 38

what conditions must organometallic,, 1,2addition irreversible reactions be done in

Answer 38

anhydrous organometallics are strong bases ,, aka they readily react with water/alcohols

Question 39

product of using organometallics

Answer 39

MgXOH LiOH

Question 40

organometallics + CO2 electrophile gives

Answer 40

carboxylic acids carboxylate salts

Question 41

halogenoalkane to carboxylic acid reaction

Answer 41

halogenoalkane + Mg + Et2O gives an organomagnesium derivative add CO2 and H3O+ forms a carboxylic acid

Question 42

an addition reaction can also be a what reaction

Answer 42

reduction reaction

Question 43

why must NaBH4 be used instead of NaH

Answer 43

NaH is a strong base bc the H- have a large charge density this is bc H is more electronegative than sodium

Question 44

where must the arrow start when drawing an addition // reduction reaction using BH4 or AlH4

Answer 44

from the X-H sigma bond

Question 45

what solvent must be used in reduction reactions // addition of metal hydrides

Answer 45

THF

Question 46

reduction reactions can also be called

Answer 46

addition reactions of metal hydrides

Question 47

borohydride anion

Answer 47

BH4 -

Question 48

borohydride anion to borohydride

Answer 48

react it with an electrophile to remove 1 of its Hs leaves u with BH3 : 6e- in the sigma bonds,, 1 empty p orbital and H-Electrophile is also a product

Question 49

ester with LiAlH4

Answer 49

primary alcohol double reduction

Question 50

ester with DIBAL

Answer 50

aldehyde

Question 51

what must be done to DIBAL before it ca be a reducing agent

Answer 51

must form a lewis acid-base complex

Question 52

ester and NaBH4

Answer 52

cant reduce esters lone pair on O,, pi donation via mesomeric effect which reduces the p+ on C,, making it less reactive

Question 53

1,2-addition of a hydride is what

Answer 53

a reduction reaction

Question 54

what does dibal look like

Answer 54

> - - Al - - < doot doot claw ,, doot doot claw then a H bonded to the Al

Question 55

limitation of LiAlH4

Answer 55

cannot be used in protic solvents

Question 56

is NaBH4 the more powerful hydride donor aka reducing agent

Answer 56

no LiAlH4 is the more powerful hydride donor aka reducing agent

Question 57

esters can be reduced to what using what

Answer 57

esters to aldehydes using DIBAL esters to primary alcohols using LiAlH4 in Et2O (double reduction)

Question 58

mechanism of ester to aldehyde

Answer 58

use dibal O: attacks the Al H of dibal attacks C lone pair on O removes O-R of ester O-R of ester attacks Al O is - Al is + electrons from O-Al bond to Al aldehyde is formed

Question 59

what is reductive amination

Answer 59

reducing imines to amines

Question 60

whats an imine again

Answer 60

R R = N R

Question 61

whats used to reduce imines to amines in reductive amination

Answer 61

Na(CN)BH3

Question 62

what is Na(CN)BH3

Answer 62

sodium cyanoborohydride toned down version of borohydride,, CN withdraws e-,, makes it a weaker reducing agent mild hydride donor

Question 63

imine to amine synthesis

Answer 63

reduction called amination uses Na(CN)BH3 as a mild reducing agent done at pH6 selective to imines instead of aldehydes//ketones

Question 64

primary amine

Answer 64

N bonded to 1c and 2 h

Question 65

secondary amine

Answer 65

N bonded to 2 c and 1 h

Question 66

tertiary amine

Answer 66

N bonded to 3 c and o H still has a lone pair tho.

Question 67

iminium ion description

Answer 67

imine: R R = N R iminium ion: R R = N(+) R R

Question 68

natures most important oxidising agent

Answer 68

NAD+

Question 69

natures most important reducing agents

Answer 69

NADPH NADH