AUS Benzyloxyacetaldehyd(3)UND DEM chirlalenBoronsäureester 4 erhielt人第三人以diastereoselektive CC-Verknüpfung巢穴Homoallylalkohol 5。Daraus wurden durch酒精标准操作8和Weiter(–)-δ-Multistriatin(1),含97%异戊二烯。
Enantioconvergent Hydroboration of a Racemic Allene: Enantioselective Synthesis of (E)-δ-Stannyl-anti-homoallylic Alcohols via Aldehyde Crotylboration
摘要:
The enantioconvergent hydroboration of racemic allenylstannane (+/-)-1 with ((d)Ipc)(2)BH converts both enantiomers of (+/-)-1 into the enantioenriched crotylborane (S)-E-3. Subsequent crotylboration of aldehydes with (S)-E-3 provides (E)-stannyl-homoallylic alcohols 5 in good yields and with excellent enantioselectivity.
Practical, highly stereoselective allyl- and crotylsilylation of aldehydes catalyzed by readily available Cinchona alkaloid amide
作者:Yuan Huang、Licheng Yang、Panlin Shao、Yu Zhao
DOI:10.1039/c3sc50973g
日期:——
constructed based on the Cinchonaalkaloid structure that promote highly stereoselectivereactions of allyl- and crotyltrichlorosilane with aromatic as well as aliphatic aldehydes (90–99% ee, >98% diastereoselectivity). The catalysts are available in a one-pot procedure in >70% yield from cheap starting materials and promote the allylation reactions at ambient temperature. Gram scale reactions with catalyst recovery
A new and more powerfully activating diamine for practical and scalable enantioselective aldehyde crotylsilylation reactions
作者:Linda M. Suen、Michael L. Steigerwald、James L. Leighton
DOI:10.1039/c3sc50714a
日期:——
A new diaminophenol ligand for crotylsilylation reactions with cis- and trans-crotyltrichlorosilane has been developed. The conformational constraints that result from the tethering of the phenol to one of the amino groups attenuate the stereoelectronic effects that reduce activity in the corresponding untethered diaminosilanes, and the resulting crotylsilane reagents are as active as our previously
A More Comprehensive and Highly Practical Solution to Enantioselective Aldehyde Crotylation
作者:Hyunwoo Kim、Stephen Ho、James L. Leighton
DOI:10.1021/ja200712f
日期:2011.5.4
The enantioselective crotylation of aldehydes with 1,2-diaminochlorocrotylsilane reagents is effectively catalyzed by Sc(OTf)(3). The one significant limitation on the utility of these reagents - substrate scope - has thus been addressed. The net result is the most comprehensive and highly practical method for enantioselective aldehyde crotylation yet advanced.
Highly Diastereo- and Enantioselective Reagents for Aldehyde Crotylation
作者:Blaine M. Hackman、Pamela J. Lombardi、James L. Leighton
DOI:10.1021/ol0480731
日期:2004.11.1
Two new, crystalline solid, storable, and highly enantioselective reagents for aldehyde crotylation have been developed. Both (cis and trans) crotylsilane reagents are easily prepared in bulk, require trivial reaction conditions, and provide the homoallylic alcohol products with near diastereo- and enantiospecificity in many cases.