Ligand Control in Co-Catalyzed Regio- and Enantioselective Hydroboration: Homoallyl Secondary Boronates via Uncommon 4,3-Hydroboration of 1,3-Dienes
作者:Mahesh M. Parsutkar、Subhajit Bhunia、Mayukh Majumder、Remy F. Lalisse、Christopher M. Hadad、T.V. RajanBabu
DOI:10.1021/jacs.3c00181
日期:——
Enantiopure homoallylic boronate esters are versatile intermediates because the C–B bond in these compounds can be stereospecifically transformed into C–C, C–O, and C–N bonds. Regio- and enantioselective synthesis of these precursorsfrom 1,3-dienes has few precedents in the literature. We have identified reaction conditions and ligands for the synthesis of nearly enantiopure (er >97:3 to >99:1) homoallylic
Diastereoselective schenck ene reaction of singlet oxygen with chiral allylic alcohols; access to enantiomerically enriched 1,2,4-trioxanes
作者:Sunil Sabbani、Louise La Pensée、John Bacsa、Erik Hedenström、Paul M. O'Neill
DOI:10.1016/j.tet.2009.08.020
日期:2009.10
3-methyl-2-butenal catalysed by (+)-MIB or (−)-MIB yielded both the enantiomers of the chiral allylic alcohols 9–11 (90–98% ee), which were subjected to diastereoselectivephotooxygenation in the presence of tetraphenylporphine (TPP) to obtain (R,R)-threo- or (S,S)-threo-β-hydroperoxy alcohols (12–14). Reaction of β-hydroperoxy alcohols (12–14) with different cyclic ketones produced optically active trioxanes
Grignard additions to α,β-unsaturated dioxolanones: preparation of chiral allylic alcohols and protected α-hydroxy aldehydes
作者:B. Heckmann、C. Mioskowski、Rama K. Bhatt、J.R. Falck
DOI:10.1016/0040-4039(96)00058-5
日期:1996.2
α,β-Unsaturated dioxolanones derived from mandelic acid smoothly add most Grignardreagents with good to excellent regio- and diastereoselectivities. The adducts are converted to chiral secondary alcohols by peroxidation at low temperature or to protected α-hydroxy aldehydes via ozonolysis.