Synthesis and Functionalization of 3-Alkylidene-1,2-diazetidines Using Transition Metal Catalysis
摘要:
An efficient two-step synthesis of a wide range of 3-methylene-1,2-diazetidines has been developed through application of a Cu(I)-catalyzed 4-exo ring closure. The double bond of this new class of strained heterocycle can be functionalized in a stereocontrolled manner by using palladium-catalyzed Heck reactions. Moreover, chemoselective reduction of 3-alkylidene-1,2-diazetidines gives access to saturated 1,2-diazetidines and vicinal diamines.
Chemo- and enantioselective Rh-catalysed hydrogenation of 3-methylene-1,2-diazetidines: application to vicinal diamine synthesis
作者:Greg P. Iacobini、David W. Porter、Michael Shipman
DOI:10.1039/c2cc35445d
日期:——
Rhodium catalysed hydrogenation of 3-methylene-1,2-diazetidines with a range of chiral ligands is reported. Using Mandyphos, excellent levels of chemo- and enantioselectivity (up to 89% ee) can be achieved. Reductive cleavage of the derived 3-substituted 1,2-diazetidine with LiDBB provides the enantioenriched biscarbamate protected 1,2-diamine.
Synthesis and Functionalization of 3-Alkylidene-1,2-diazetidines Using Transition Metal Catalysis
作者:Michael J. Brown、Guy J. Clarkson、Graham G. Inglis、Michael Shipman
DOI:10.1021/ol200193n
日期:2011.4.1
An efficient two-step synthesis of a wide range of 3-methylene-1,2-diazetidines has been developed through application of a Cu(I)-catalyzed 4-exo ring closure. The double bond of this new class of strained heterocycle can be functionalized in a stereocontrolled manner by using palladium-catalyzed Heck reactions. Moreover, chemoselective reduction of 3-alkylidene-1,2-diazetidines gives access to saturated 1,2-diazetidines and vicinal diamines.
Synthesis of 4,5-Diazaspiro[2.3]hexanes and 1,2-Diazaspiro[3.3]heptanes as Hexahydropyridazine Analogues
作者:Alpa K. Pancholi、Greg P. Iacobini、Guy J. Clarkson、David W. Porter、Michael Shipman
DOI:10.1021/acs.joc.7b02622
日期:2018.1.5
5-Diazaspiro[2.3]hexanes are made by dihalocarbene addition across the exocyclic double bond of readily accessible 3-alkylidene-1,2-diazetidines. Using difluorocarbene, generated from TMSCF3/NaI, these spirocycles were produced in yields up to 97% by stereospecific addition across the alkene. Lower yields (up to 64%) were observed using more reactivedichlorocarbene, due to competitive insertion of the carbene