Hofmann Elimination

R3N(CH3)+ + OH− → alkene + R3N + H2O

ภาพรวม

The Hofmann elimination converts a quaternary ammonium salt to an alkene, amine, and water upon heating with base. Unlike E2 elimination, Hofmann elimination favors the less substituted alkene (anti-Zaitsev). This reaction was historically used to determine amine structures by exhaustive methylation and elimination.

ผู้เข้าร่วม

บทบาท สาร สัมประสิทธิ์ สถานะ
ผลิตภัณฑ์ Water H₂O 1 (l)

ตัวอย่างในชีวิตประจำวัน

Hofmann elimination was crucial in determining the structures of complex alkaloids like morphine and quinine before modern spectroscopy.

ความสำคัญทางอุตสาหกรรม

While largely replaced by spectroscopic methods for structure determination, Hofmann elimination is still useful in synthetic chemistry for specific alkene preparations.

คุณสมบัติ

ประเภท
Organic
ย้อนกลับได้
ไม่
พลังงาน
คายความร้อน
ΔH
-40.0 kJ/mol
ตัวเร่งปฏิกิริยา
Ag₂O (for quaternary salt formation)

ปฏิกิริยาที่เกี่ยวข้อง

Epoxidation of Alkenes (mCPBA) Swern Oxidation Oxidation of Secondary Alcohol to Ketone E2 Elimination (Dehydrohalogenation) Claisen Condensation (Ethyl Acetate) Aldol Condensation of Acetaldehyde Kolbe Electrolysis Baeyer-Villiger Oxidation Beckmann Rearrangement (Cyclohexanone Oxime) Dehydration of Ethanol

Frequently Asked Questions

What is the equation for Hofmann Elimination?
The balanced equation is: R₃N(CH₃)⁺ + OH⁻ → alkene + R₃N + H₂O.
What type of reaction is Hofmann Elimination?
Hofmann Elimination is a organic reaction.
Is Hofmann Elimination exothermic or endothermic?
Hofmann Elimination is exothermic (releases energy). The enthalpy change (ΔH) is -40.0 kJ/mol.
What conditions are needed for Hofmann Elimination?
This reaction requires a catalyst (Ag₂O (for quaternary salt formation)).