1366421-69-3

Upstream product

• 3182-95-4 L-Phenylalaninol 
• 101-83-7 N-cyclohexyl-cyclohexanamine 
• 1795-98-8 rac-phenylalaninol 
• 1366421-67-1 (S)-2-(2,3-bis(dicyclohexylamino)cyclopropenimine)-3-phenylpropan-1-ol hydrochloride 

Relevant academic research and scientific papers

Structure-activity relationship studies of cyclopropenimines as enantioselective Bronsted base catalysts

We recently demonstrated that chiral cyclopropenimines are viable Bronsted base catalysts in enantioselective Michael and Mannich reactions. Herein, we describe a series of structure-activity relationship studies that provide an enhanced understanding of the effectiveness of certain cyclopropenimines as enantioselective Bronsted base catalysts. These studies underscore the crucial importance of dicyclohexylamino substituents in mediating both reaction rate and enantioselectivity. In addition, an unusual catalyst CH...O interaction, which provides both ground state and transition state organization, is discussed. Cyclopropenimine stability studies have led to the identification of new catalysts with greatly improved stability. Finally, additional demonstrations of substrate scope and current limitations are provided herein.

Cyclopropenimine-catalyzed enantioselective mannich reactions of tert -butyl glycinates with N -Boc-imines

Cyclopropenimine 1 is shown to catalyze Mannich reactions between glycine imines and N-Boc-aldimines with high levels of enantio- and diastereocontrol. The reactivity of 1 is shown to be substantially greater than that of a widely used thiourea cinchona alkaloid-derived catalyst. A variety of aryl and aliphatic N-Boc-aldimines are effective substrates for this transformation. A preparative-scale reaction to deliver >90 mmol of product is shown using 1 mol % catalyst. The products of this transformation can be converted into several useful derivatives.

CYCLOPROPENIMINE CATALYST COMPOSITIONS AND PROCESSES

The present invention provides, inter alia, a cyclopropenimine Br?nsted base catalyst and a cyclopropenimine scaffold for use as a Br?nsted base catalyst. This cyclopropenimine has the structure (100). Methods for making such a cyclopropenimine are also provided. Further provided are processes for carrying out an organic synthetic reaction and processes for catalyzing a proton transfer reaction enantioselectively using such a cyclopropenimine Br?nsted base catalyst.

Enantioselective Bronsted base catalysis with chiral cyclopropenimines

Cyclopropenimines are shown to be a highly effective new class of enantioselective Bronsted base catalysts. A chiral 2,3-bis(dialkylamino) cyclopropenimine catalyzes the rapid Michael reaction of a glycine imine substrate with high levels of enantioselectivity. A preparative scale reaction to deliver 25 g of product is demonstrated, and a trivial large scale synthesis of the optimal catalyst is shown. In addition, the basicity of a 2,3-bis(dialkylamino)cyclopropenimine is measured for the first time and shown to be approximately equivalent to the P1-tBu phosphazene base. An X-ray crystal structure of the protonated catalyst is shown along with a proposed mechanistic and stereochemical rationale.