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A Novel Type of Chiral Triangulane‐Based Diphosphane Ligands for Transition Metals
Author(s) -
Khlebnikov Alexander F.,
Kozhushkov Sergei I.,
Yufit Dmitry S.,
Schill Heiko,
Reggelin Michael,
Spohr Volker,
de Meijere Armin
Publication year - 2012
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201101715
Subject(s) - chemistry , moiety , denticity , stereochemistry , pentane , transition metal , medicinal chemistry , catalysis , crystallography , organic chemistry , crystal structure
A new original strategy for the synthesis of axially and helically chiral bidentate diphosphane ligands featuring a rigid triangulanyl backbone has been elaborated and executed for several representative enantiomerically pure ligands. Thus,(1 R ,3 S ,4 S )‐1,4‐bis[(diphenylphosphanyl)methyl]spiro[2.2]pentane [(1 R ,3 S ,4 S )‐ 24· (BH 3 ) 2 ], [(1 R ,3 R ,4 S )‐4‐(diphenylphosphanyl)methylspiro[2.2]pentan‐1‐yl]diphenylphosphane [(1 R ,3 R ,4 S )‐ 27· (BH 3 ) 2 ], [(1 R ,3 R ,4 S ,5 R )‐5‐(diphenylphosphanyl)methyldispiro[2.0.2.1]heptan‐1‐yl]diphenylphosphane [(1 R ,3 R ,4 S ,5 R )‐ 30· (BH 3 ) 2 ], (1 S ,3 S ,4 S )‐1,4‐bis(diphenylphosphanyl)spiropentane [(1 R ,3 S ,4 S )‐ 35· (BH 3 ) 2 ], (1 S ,3 S ,4 S )‐1,4‐bis(diphenylphosphanyl)spiropentane [(1 S ,3 S ,4 S )‐ 35· (BH 3 ) 2 ], (1 S ,3 S ,4 S )‐1,4‐bis(diphenylphosphanyl)spiropentane [(1 R ,3 R ,4 S )‐ 35· (BH 3 ) 2 ], and (1 R ,3 R ,4 R ,5 R )‐1,5‐bis(diphenylphosphanyl)dispiro[2.0.2.1]heptane [(1 R ,3 R ,4 R ,5 R )‐ 36· (BH 3 ) 2 ] with a spiropentyl and a dispiro[2.0.2.1]heptyl moiety, respectively, have been prepared as bishydroborane complexes applying repetitively the same set of standard synthetic operations, starting from [(1 S ,3 R )‐4‐methylenespiropent‐1‐yl]methyl acetate [(1 S ,3 R )‐ 7 ], (4,4‐dibromospiropent‐1‐yl)methanols [(1 S ,3 R )‐ 8 and (1 R ,3 S )‐ 8 ] and (dibromodispiro[2.0.2.1]heptyl)methanols (1 R ,3 S ,4 R )‐ 9 , (1 S ,3 R ,4 S )‐ 9 and (1 S ,3 R ,4 R )‐ 9 in 4–7 steps. The relative configurations of all important intermediates as well as the absolute configurations of the key intermediates and most final products were established by X‐ray crystal structure analyses.