N-(Alkylsulfamoyl)aldimines: Easily deprotected precursors for diarylmethylamine synthesis
The sequential reaction of chlorosulfonyl isocyanate with t-BuOH, t-BuNH2 and TFA allows formation of H2NSO 2NHBut. Condensation of the latter with Ar1CHO in the presence of Ti(OEt)4 provides the activated imines Ar 1CHNSO2NHBut (59-89%). Commercially available boronic acids add to these imines with good stereoselectivity (76-98% ee) using readily available diene ligands. Simple deprotection with 5% w/w water in pyridine affords free Ar1CHNH2Ar2.
Crampton, Rosemary H.,Fox, Martin,Woodward, Simon
p. 599 - 605
(2013/06/27)
Inversion or retention? Effects of acidic additives on the stereochemical course in enantiospecific suzuki-miyaura coupling of α-(acetylamino) benzylboronic esters
The stereochemical course of the stereospecific Suzuki-Miyaura coupling of enantioenriched α-(acetylamino)benzylboronic esters with aryl bromides can be switched by the choice of acidic additives in the presence of a Pd/XPhos catalyst system. Highly enant
Bis-sulfamyl imines: Potent substrates for asymmetric additions of arylboroxines under rhodium catalysis
Bis-sulfamyl imines are shown to be potentially ideal substrates for rhodium-catalysed asymmetric additions of arylboron nucleophiles as they show: (i) near perfect enantioselectivities (11 examples, 98-99+% ee), (ii) good to excellent diastereoselectivities (10-32:1 rac:meso), and (iii) high functional group tolerance in removal of the low molecular weight protecting group via mild heating in aqueous pyridine.
Crampton, Rosemary,Woodward, Simon,Fox, Martin
supporting information; experimental part
p. 903 - 906
(2011/06/19)
Stereospecific Suzuki-Miyaura coupling of chiral α-(Acylamino) benzylboronic esters with inversion of configuration
The first invertive B-alkyl Suzuki-Miyaura coupling has been achieved. The coupling of enantioenriched α-(acylamino)benzylboronic esters with aryl bromides and chlorides took place efficiently in toluene at 80 °C in the presence of Pd(dba)2 (5 mol %), XPhos (10 mol %), K 2CO3 (3 equiv), and H2O (2 equiv). The reaction proceeded with inversion of configuration to give diarylmethanamine derivatives in high yields with high conservation of enantiomeric excesses.
Iridium-monodentate phosphoramidite-catalyzed asymmetric hydrogenation of substituted benzophenone N-H imines
-
Hou, Guohua,Zhang, Xumu,Tao, Ran,Sun, Yongui,Gosselin, Francis
supporting information; experimental part
p. 2124 - 2125
(2010/04/28)
Enantioselective hydrogenation of N-H imines
(Figure Presented) N-H ketoimines 3a-3v are readily prepared in high yield via organometallic addition to nitriles and isolated as corresponding bench-stable hydrochloride salts. Homogeneous asymmetric hydrogenation of unprotected N-H ketoimines 3a-3v usi
Hou, Guohua,Gosselin, Francis,Li, Wei,McWilliams, J. Christopher,Sun, Yongkui,Weisel, Mark,O'Shea, Paul D.,Chen, Cheng-Yi,Davies, Ian W.,Zhang, Xumu
supporting information; experimental part
p. 9882 - 9883
(2009/12/06)
More Articles about upstream products of 1351866-39-1