{"id":601,"date":"2022-03-08T06:16:00","date_gmt":"2022-03-08T06:16:00","guid":{"rendered":"http:\/\/box5250.temp.domains\/~aceorgan\/blog\/?p=601"},"modified":"2022-03-09T23:34:47","modified_gmt":"2022-03-09T23:34:47","slug":"sn1-vs-sn2-e1-e2-sn1-sn2","status":"publish","type":"post","link":"https:\/\/www.aceorganicchem.com\/blog\/sn1-vs-sn2-e1-e2-sn1-sn2\/","title":{"rendered":"SN1 vs SN2. E1, E2, SN1, or SN2? [with printable chart]"},"content":{"rendered":"\n

SN<\/sub>1 vs SN<\/sub>2. Is it SN<\/sub>1, SN<\/sub>2, E1, E2?<\/h1>\n\n\n\n

This is such a common question, not only for students but on exams too. \u00a0How do you tell if it is SN<\/sub>1 vs. SN<\/sub>2? How the heck do you tell the difference between an E1, E2, SN1, SN2 reaction? \u00a0Check out the chart below to start.<\/p>\n\n\n\n

The factors that will decide SN<\/sub>1 vs SN<\/sub>2 and whether it is SN<\/sub>1, SN<\/sub>2, E1, E2:<\/strong><\/h2>\n\n\n\n

1) Do you have a strong nucleophile? \u00a0If you do, it will favor an SN<\/sub>2 reaction in the SN<\/sub>1 vs SN<\/sub>2 fight. \u00a0If it is a mediocre nucleophile, it will favor an SN<\/sub>1 reaction.\u00a0 This is because of the two mechanisms.\u00a0 In the SN<\/sub>1, we have an open position (carbocation), so any old nucleophile can just waltz in and form a bond.\u00a0 In the SN<\/sub>2, we are pushing off the leaving group, which requires a stronger nucleophile.\u00a0 What is a strong nucleophile? \u00a0Check out these blog posts on strong nucleophiles<\/a> and strong electrophiles<\/a>.<\/p>\n\n\n\n

2) Does your nucleophile double as a base? If yes, it is going to favor elimination (E1\/E2) over substitution (SN<\/sub>1\/SN<\/sub>2).\u00a0 Bases want to take protons, which leads to elimination.<\/p>\n\n\n\n

3) How good is your leaving group? \u00a0If it is awesome, it is more likely to be a carbocation intermediate, ie E1 or SN<\/sub>1 reaction. \u00a0If the leaving group is only OK, that means it has to be forced off and is more likely to be a concerted reaction mechanism like SN<\/sub>2 or E2.<\/p>\n\n\n\n

4) What is your solvent? Polar protic solvents will stabilize a carbocation better, therefore promote an E1 or SN<\/sub>1 reaction. \u00a0Polar aprotic solvents favor SN<\/sub>2 and E2.\u00a0 This is because a protic solvent is more likely to stabilize a carbocation intermediate and therefore promote the E1\/SN1 pathway.<\/p>\n\n\n\n

5) What kind of substrate do you have? \u00a0If your starting material is a tertiary substrate, you are definitely E1 or SN<\/sub>1. \u00a0If it is a primary substrate, \u00a0you are definitely SN<\/sub>2 or E2. If it is a secondary substrate, it could go any one of the ways.<\/p>\n\n\n\n

The SN<\/sub>1 vs. SN<\/sub>2 video: <\/strong><\/h3>\n\n\n\n

Here are two videos were are particularly fond of that coach you through the way to decide which of these things it is. <\/p>\n\n\n\n

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