SmI2-Mediated Radical Cyclizations Directed by a C−Si Bond
摘要:
The use of a silicon stereocontrol element in cyclobutanol and cyclopentanol-forming cyclizations mediated by SmI2 results in excellent diastereocontrol. The C-Si bond in the products of cyclization provides a versatile handle for further manipulation. An asymmetric route to cyclization substrates involving copper-catalyzed silyl transfer has also been developed.
Catalytic enantioselective addition of diethylzinc to 1,3-dithian-2-yl substituted aliphatic aldehydes: a new approach to optically active 2-(hydroxyalkyl)-1,3-dithianes
摘要:
Asymmetric synthesis of 2-(hydroxyalkyl)-1,3-dithianes was achieved in good yields of up to 81% by using various 1,3-dithian-2-yl-substituted aliphatic aldehydes as substrates in the catalytic enantioselective addition of diethylzinc, With fair enantiomeric ratios of up to 85:15 in the enantiocontrolled ethylation step this synthetic approach provides an entry towards potential chiral building blocks. (C) 2000 Elsevier Science Ltd. All rights reserved.
SmI<sub>2</sub>-Mediated Radical Cyclizations Directed by a C−Si Bond
作者:Hassan Y. Harb、Karl D. Collins、Jose V. Garcia Altur、Sue Bowker、Leonie Campbell、David J. Procter
DOI:10.1021/ol102278c
日期:2010.12.3
The use of a silicon stereocontrol element in cyclobutanol and cyclopentanol-forming cyclizations mediated by SmI2 results in excellent diastereocontrol. The C-Si bond in the products of cyclization provides a versatile handle for further manipulation. An asymmetric route to cyclization substrates involving copper-catalyzed silyl transfer has also been developed.
Catalytic enantioselective addition of diethylzinc to 1,3-dithian-2-yl substituted aliphatic aldehydes: a new approach to optically active 2-(hydroxyalkyl)-1,3-dithianes
Asymmetric synthesis of 2-(hydroxyalkyl)-1,3-dithianes was achieved in good yields of up to 81% by using various 1,3-dithian-2-yl-substituted aliphatic aldehydes as substrates in the catalytic enantioselective addition of diethylzinc, With fair enantiomeric ratios of up to 85:15 in the enantiocontrolled ethylation step this synthetic approach provides an entry towards potential chiral building blocks. (C) 2000 Elsevier Science Ltd. All rights reserved.