CMBP, also known as Tsunoda reagent, is a stabilized trialkylphosphorane that serves as a versatile substitute for diethyl azodicarboxylate and triphenylphosphine in Mitsunobu reactions. It exhibits comparable performance to triphenylphosphine and diethyl azodicarboxylate while combining their advantageous properties within a single molecule. What sets CMBP apart is its enhanced reactivity and compatibility with high temperatures, enabling the utilization of weakly acidic pronucleophiles beyond the typical pKa range for Mitsunobu reactions. Additionally, CMBP offers a clean reaction profile, eliminating the need for phosphine nucleophile reagents and generating acetonitrile as an innocuous by-product, which often makes the process of purification simple. The CMBP-mediated reaction can be conducted at room temperature, yielding the desired product with exceptional yield and purity, but may require more time.
Synonyms: (Cyanomethylene)tributylphosphorane, CMBP, 2-(Tributylphosphoranylidene)acetonitrile, (Tributylphosphoranylidene)acetonitrile, 2-(tributyl-lambda5-phosphanylidene)acetonitrile