Unlocking the N² Selectivity of Benzotriazoles: Regiodivergent and Highly Selective Coupling of Benzotriazoles with Allenes

Abstract

The rhodium-catalyzed, highly N(2) - and N(1) -selective coupling of benzotriazoles with allenes is reported. The exceptionally high N(2) and N(1) selectivities were achieved by using a rhodium(I)/DPEphos and rhodium(I)/JoSPOphos catalyst, respectively. This method permits the atom-economic synthesis of valuable branched N(2) - and N(1) -allylated benzotriazole derivatives and allows for preliminary studies of their reactivity.

Coordination chemistry and catalysis with secondary phosphine oxides

“…A few years ago Breit and coworkers 262 The catalytic system was robust and tolerated many modifications on the benzotriazole and the allene. Given that JoSPOphos is chiral, P-stereogenic SPO, some enantioinduction could be expected and indeed a 46% ee was observed.…”

Regioconvergent and Enantioselective Rhodium‐Catalyzed Hydroamination of Internal and Terminal Alkynes: A Highly Flexible Access to Chiral Pyrazoles

“…Third, coincidently, the last effect might also decrease the enantioselectivity, since this selectivity is engendered by coordination of the rhodium–ligand species with the π‐allyl system ( A I in Scheme ) . Thus, we anticipated that there might be an opportunity to control the N‐selectivity as well as the enantio‐ and regioselectivities of the obtained products by using our previously established Rh/JoSPOPhos system ,,…”

Rhodium-catalyzed addition of sulfonyl hydrazides to allenes: regioselective synthesis of branched allylic sulfones

“…The reaction was performed according to the modified literature procedure [4]. 3ab (157.2 mg, 0.5 mmol) was dissolved in CH2Cl2 (5.0 ml, 0.1 M) and cooled to -78 o C. Ozone was directly bubbled in the solution.…”