Glyceraldehyde 3-Phosphate

The chemical thermodynamic properties acyl phosphates and phosphate esters drives bioenergetics.

Organic phosphorus compounds don't get much attention in your typical organic chemistry course. This reflects the long-standing focus in the organic chemistry curriculum on bench-top organic synthesis rather than the chemistry of living systems. If biochemistry professors had more of a say in the organic chemistry syllabus, organic phosphorus compounds would be a primary focus alongside aldehydes and ketones. The organic chemistry important for the MCAT is the organic chemistry that is important for biochemistry, so reactions like phosphoryl transfer or acyl substitution with phosphate anhydrides are among the most important to master in preparation for the exam.

WikiPremed Resources

Reaction of Alcohols with Phosphorus Tribromide
Mechanisms and explanations from the Organic Mechanisms Pocketbook

The Wittig Reaction
Mechanisms and explanations from the Organic Mechanisms Pocketbook

Reactions of Organic Phosphorus Compounds Images
Image gallery for study with links to larger teaching JPEGs for classroom presentation

Question Drill for Organic Phosphorus Compounds
Conceptual Vocabulary Self-Test

Basic Terms Crossword Puzzle

Basic Puzzle Solution

Learning Goals


Be familiar with the structural formulas and nomenclature for the range of oxidation states of organic phosphorus compounds from phosphines to phosphate esters.

Be able to picture the deprotonation states at physiological pH of phosphoric acid species and organic mono-, di-, and tri-phosphates.

Be able to picture the general mechanism of phosphoryl transfer reactions and understand their transcendent importance in biochemistry.

Understand the mechanism of the phosphorylation of glucose by ATP and appreciate its importance as a critical metabolic step.

Understand the structure of a phosphorus ylide, such as plays a role in the Wittig Reaction.

Suggested Assignments

Review the basic terms for reactions of organic phosphorus compounds using the question server. Complete the fundamental terms crossword puzzle. Here is the solution to the puzzle.

Review the web resources for reactions of organic phosphorus compounds.

Conceptual Vocabulary for Organic Phosphorus Compounds

Phosphorus is the chemical element that has the symbol P and atomic number 15.
Phosphodiester bond
A phosphodiester bond is a group of strong covalent bonds between the phosphorus atom in a phosphate group and two other molecules over two ester bonds. Such bonds make up the backbone of DNA.
An organophosphate is the general name for esters of phosphoric acid.
A phosphonate is a phosphonic acid, its conjugate base, or the ester of a phosphonic acid.
Phosphine is the common name for phosphorus hydride, also known by the IUPAC name phosphane and, occasionally, phosphamine.
Phosphonic acid
Within organic chemistry, a phosphonic acid contains an organic portion bound to a phosphorus which is singly bonded to two hydroxyl oxygens and doubly bonded to a third oxygen.
Phosphorus tribromide
Phosphorus tribromide is widely used in the laboratory for the conversion of alcohols to alkyl bromides.
The phosphonium cation is a positively charged polyatomic ion in which a phosphorus atom is bound to four hydrogens.
Triphenylphosphine is a common organophosphorus compound in which a single phosphorus is bound to three phenyl groups.
Phosphonium salt
Alkyltriphenyl-phosphonium salts are widely used for the preparation of Wittig reagents for the Wittig reaction.
Phosphite ester
Phosphite esters are esters of phosphorous acid in which all three oxygens form ester linkages with carbon.
Wittig reaction
The Wittig reaction is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide to give an alkene and triphenylphosphine oxide.
BINAP is an acronym for an important chiral ligand widely used in asymmetric synthesis, which consists of two naphthyl groups linked by a single bond with diphenylphosphino groups at the end of each naphthyl group.
Phosphoryl chloride
Phosphoryl chloride is used to make phosphate esters. It contains phosphorus in a double bond with oxygen and singly bonded to three chlorine atoms.
Advanced terms that may appear in context in MCAT passages
Appel reaction
The Appel reaction is an organic reaction that converts an alcohol into an alkyl chloride using triphenylphosphine and carbon tetrachloride.
Horner-Wadsworth-Emmons reaction
The Horner-Wadsworth-Emmons reaction is the chemical reaction of stabilized phosphonate carbanions with aldehydes or ketones to produce predominantly E-alkenes.
Perkow reaction
The Perkow reaction is an organic reaction in which a trialkyl phosphite ester reacts with a haloketone to form a vinyl phosphonate and an alkyl halide.
Staudinger reaction
The Staudinger reaction is a chemical reaction in which the combination of an azide with a phosphine or phosphite produces an iminophosphorane intermediate. This reaction is the first step in a mild method of reducing an azide to an amine.