Stereoselective Synthesis of Cyclic Guanidines by Directed Diamination of Unactivated Alkenes
作者:Artur K. Mailyan、Kyle Young、Joanna L. Chen、Bradley T. Reid、Armen Zakarian
DOI:10.1021/acs.orglett.6b02778
日期:2016.11.4
method for a directed stereoselective guanidinylation of alkenes is described. The guanidine unit can be delivered as an intact fragment by a hydroxy or carboxy group, usually with a high level of stereocontrol. After the guanidine delivery, the directinggroup can be cleaved under exceptionally mild conditions, typically by alcoholysis in the presence of acetic acid. Broad functionalgroup tolerance
Catalyzed by PdCl2, SnCl2 can efficiently mediate the allylation of various aldehydes with allyl chloride or bromide, but not with allyl alcohol, in fully aqueous media. The yield of the reaction is very high (90–100%), and the reaction is operationally simple, environmental benign and easy to scale up.
A Mild and Convenient Barbier-Type Allylation of Aldehydes to Homoallylic Alcohols via Iodide Ion Promoted Stannylation of Allylic Bromides and Chlorides with Tin(II) Chloride
作者:Toshiro Imai、Shinya Nishida
DOI:10.1055/s-1993-25871
日期:——
Barbier-type allylation of aldehydes with allylic bromides and tin(II) chloride dihydrate is largely accelerated by adding stoichiometric or substoichiometric amounts of sodium iodide. This method has some merits such as lower temperature, shorter reaction time and/or more choices of solvents for the reaction. Moreover, the activation by the iodide ion enables the use of relatively unreactive allylic chlorides of various structural types (e.g., 3-chloro-2-chloromethylpropene as an isobutene dianion equivalent) and, thus, expands synthetic applicability of this reaction. The major role of the iodide salt is attributed to the in situ generation of the corresponding allylic iodide.
A compound represented by the general formula (I) or a salt thereof:
[T represents oxygen atom and the like; V represents CH
2
and the like; R
O1
to R
O4
represent hydrogen atom and the like; A represents a linear alkylene group or linear alkenylene group having 2 to 8 carbon atoms and the like; D represents carboxyl group and the like; X represents ethylene group, trimethylene group and the like; E represents —CH(OH)— group and the like; and W represent —U
1
—(R
W1
)(R
W2
)—U
2
—U
3
group (U
1
represents a single bond, an alkylene group having 1 to 4 carbon atoms and the like; R
W1
and R
W2
represent hydrogen atom and the like; U
2
represents a single bond, an alkylene group having 1 to 4 carbon atoms and the like; and U
3
represent an alkyl group having 1 to 8 carbon atoms and the like), or a residue of a carbon ring or heterocyclic compound], which can be utilized as an active ingredient of medicaments effective for prophylactic and/or therapeutic treatment of skeletal diseases such as osteoporosis and fracture, glaucoma, ulcerative colitis and the like.
ALDEHYDE-SELECTIVE WACKER-TYPE OXIDATION OF UNBIASED ALKENES
申请人:CALIFORNIA INSTITUTE OF TECHNOLOGY
公开号:US20140316149A1
公开(公告)日:2014-10-23
This disclosure is directed to methods of preparing organic aldehydes, each method comprising contacting a terminal olefin with an oxidizing mixture comprising:
(a) a dichloro-palladium complex;
(b) a copper complex;
(c) a source of nitrite;
under aerobic reaction conditions sufficient to convert at least a portion of the terminal olefin to an aldehyde.